this is bbc news, the headlines at midday. home secretary amber rudd calls on technology firms such as whatsapp to allow security services access to encrypted messages in terrorism cases. there should be no place for terrorists to hide, we need to make sure that organisations like whatsapp, and there are plenty of others like that, don't provide a secret place for terrorists to communicate with each other. scotland yard says the westminster attacker khalid masood acted alone and his motive may never be known. detectives confirmed the attack lasted just 82 seconds. the family of murdered pc keith palmer has thanked those who fought to save his life and said they are grateful he was not alone. more than 30 people have been injured, two seriously, after a suspected gas explosion on merseyside. the pentagon investigates a us—led coalition air strike in the iraqi city of mosul, where dozens of civilians were reportedly killed. also in the next hour,

the beginning of the end to mercedes‘ formula one dominance? ferrari's sebastian vettel pips lewis hamilton to the chequered flag in the first race of the season in melbourne, his first win since 2015. coming up in half an hour, the final episode of click‘s special india season. good afternoon and welcome to bbc news. police say they might never find out why khalid masood killed four people near the houses of parliament on wednesday. scotland yard now say they believe he was acting alone and that the attack was over within 82 seconds. meanwhile, the home secretary, amber rudd, has said she is ready to take action against internet

companies if they won't work with the security services during terrorism investigations. alexandra mackenzie reports. 82 seconds, that's all it took. in that time, khalid masood caused the deaths of three people on westminster bridge, and injured many more. he crashed his car into the railings, ran through a gate at the houses of parliament, and stabbed pc keith palmer to death. last night, his family paid tribute to his selfless bravery, saying... police believe that masood carried out the terror attack on his own but are trying to establish if he was encouraged or directed by others. questions remain unanswered about his route to radicalisation. he was a violent criminal

before converting to islam more than a decade ago. since wednesday, 11 people have been arrested. all have now been released, except for a 58—year—old manfrom birmingham. detained under the terrorism act, he can be held without charge for 14 days. members of the public have come to the scene of wednesday's attack to pay their respects to the four people who lost their lives, also to remember the many who were injured and those who remain in hospital. alexandra mackenzie, bbc news. well, the investigation continues as the home secretary issues a fresh call for a crackdown by social—media companies against online extremism. earlier, i spoke to our correspondent nick bea ke at westminster, who gave us the latest. this is where tributes to the victims of the attack are continuing to grow. lots of messages have been left this morning.

police officers, londoners, tourists, taking time to stand and think and contemplate what happens last wednesday. the events that we saw have prompted the home secretary to renew her fire when it comes to the big social—media companies. we have seen criticism of the likes of google and facebook before. but the home secretary was singling out a few smaller companies, her concern is on two levels. first of all, platforms which are encrypted, so people can send messages which police and security services aren't able to intercept. but also that they are, in effect, a platform for hatred and poisonous ideology to be shared. this is what the home secretary, amber rudd, said on the andrew marr programme this morning. it is completely unacceptable. there should be no place for terrorists to hide. we need to make sure that organisations like whatsapp do not provide a secret place for terrorists to communicate with each other. it used to be that people would steam open envelopes orjust listen in on phones

when they wanted to find out what people were doing — legally. but in this situation we need to make sure that our intelligence services have the ability to get into situations like encrypted whatsapp. this is the same situation that is going on between apple and the fbi in washington, where tim cook of apple has so far said they are not going to allow the american authorities to open a back door into their apps, and yet if they don't, this end—to—end encryption continues. do they have to take on the big internet companies and force them to open their devices? if i was talking to tim cook, i would say this is something completely different. we do want them to recognise they have a responsibility to engage with government, to engage with law enforcement agencies when there is a terrorist situation. we would do it all through carefully thought through and legal arrangements.

they cannot get away with saying, "we are a different situation" — they are not. tim cook of apple says it would be wrong for the government to force us to open a back door into our products. and yet without that, you can't find out what you need to find out. i would ask him to look at other ways of helping us. it is not necessarily apple itself, it is sometimes other situations. which is why i am calling in a lot of the organisations relevant to that this week to ask them to work with us to deliver the answer. it is not about them standing back from us, this is a national problem. who are you calling in? a long list? i would rather not be going to who we are calling in, it is a long list, but it is also the smaller companies as well. to make sure there is no hiding

place for terrorist. i want to make sure everybody takes responsibility for this. this debate is central to what happened here. we know that khalid masood, the man who carried out the attack, checked whatsapp on his phone on wednesday just three minutes before he launched that deadly assault. it was at 2:37pm, just before he drove across westminster bridge carrying out the attack, and stabbed pc keith palmer in the grounds of westminster. whatsapp is one of those companies which the home secretary is keen to speak to, she is having a meeting with a number of social—media providers, hoping to build bridges and work together with them. we now know from the police that they in terror attack lasted only 82 seconds, that is quite extraordinary, isn't it? yes, less than a minute and a half. it could have taken place over a much longer time frame, were it not for the fact that a close protection officer who happen to have a sidearm was able to kill the attacker. it may well have been that the terrible events would have played out even longer, but 82 seconds was all that it

took for this deadly assault to take place. the police have been working to establish the motive for this, but it was very telling overnight but we heard from a senior counter—terrorism officer, saying we may never know why this man carried out this attack. the police insist he was probably inspired by international terrorism, but they have arrested 11 people. one man remains in custody. but it is quite interesting, the police have been quite honest in saying it may be the case that in terms of motive, that is something that this man may have gone to his grave knowing, and it may be impossible to find out why he carried this out. the director of europol, rob wainright, has also warned this morning about online extremism. i asked him whether the home secretary was right to say

the intelligence services must have access to encrypted messaging services. well, i think it is a reasonable call by the home secretary, what we're seeing across the hundreds of cases that europol has been supporting is that encryption is becoming more and more of a feature of those cases, more and more of a means by which terrorists are attempting to communicate in a secure way. and a really significant challenge for the police to get beyond that. at the heart of it, reeta, is this stark inconsistency that the police have the means by which to carry out lawful interception of telephone calls, but not a similar means that those communications if they appear through a social—media platform, and that doesn't seem right. there is an inconsistency that has not yet been fixed by the right legislation or the right kind of interaction between government and technology partners. and that was rob wainwright of europol. the former ukip leader nigel farage

has said that mp douglas carswell, who resigned from the party yesterday, has a duty to trigger a by—election in his clacton consituency. mr carswell isn't going back to the conservatives — instead he'll sit as an independent. he quit amid a long—running feud with mr farage about future ukip strategy. a short while ago, mr farage told me that he'd caused "endless division" in the party. oh, it is, absolutely. this guy has been working against the party consistently for the last two years. he never supported, from day one, many of the key planks the party believes in, he was sincere on brexit but nothing else, he caused endless division, and i am very pleased he is gone, particularly pleased for paul nuttall, who has now got a chance to lead a unified party. douglas carswell there, that was always going to be impossible. but douglas carswell was elected on a ukip ticket, something which, respectfully, you didn't manage to do, neither did the present leader of the party. just remember this — clacton is demographically the number—one eurosceptic seat

in this country, and i would say this, a lot of people who voted him into parliament did not vote just because of him, they voted ukip, he has given up the label on which he was elected, and this is the man who led the charge in parliament for real recall, to give people a mechanism by which at 20% of the constituency, if they voted to have a by—election, they should legally be able to have one. so what we will do is take him at his word, and we will now write to every house in clacton and ask them, "do you want a by—election or not?" if more than 20% say they do, we will find outjust how honourable mr ca rswell is. but technically he doesn't have to have a by—election, he maintains because he is not moving party, he doesn't have to have one. of course he does, he was voted in as a ukip candidate, and it is a constituency in which ukip is very, very strong. i could be wrong, but i suspect there will be a lot of very angry ukip voters in clacton this morning.

what you make of this central point that ukip has achieved what it set out to achieve? brexit is going to happen, it is happening this week, that is why he is going, job done very successfully. we have won the war, we now have to win the peace, and i am very concerned, i see the government backtracking on taking back territorial fishing waters, i hearfrom amber rudd that she once us to stay part of the european arrest warrant, she wants european court ofjustice in luxembourg still to have supremacy in some areas. this is farfrom over. do you fear that, once again, ukip is in the headlines because of internal infighting, rather than because of what you stand for? virtually every bad story about ukip that has emerged for the last two and a half years has come as a result of splits with douglas carswell, a tiny handful of people that were his key supporters, and i think, actually,

in terms of splits, i think today is a very good unifying day for the party, i am hearing that already. so a prediction from nigel farage that it will be harmony from now on within ukip? well, i don't think there will be big ideological divides, everyone in the senior positions agrees with the manifesto, understands how important immigration is as an issue to britain voters, and for two and a half years we had douglas carswell trying to get rid of that policy — has ended. more than 30 people have been hurt, two of them seriously, after a suspected gas explosion in merseyside. a dance centre for children was destroyed and customers at a chinese restaurant were caught in the blast near birkenhead. andy gill sent this report. the scale of the devastation shows just how powerful the explosion was — one building housing three businesses totally destroyed. this is what it looked like before last night.

the blast was heard up to six miles away. an almighty bang, but as well as the bang there was pressure as well, i felt a lot of pressure, my window was shut, i thought initially it was in the house, i've ran around like a maniac for a minute, looking round obviously to see if my house is still in tact and stuff like that. the sound of the building blowing up was captured by a car's dashboard camera. what was that?! two people were taken to a trauma unit in liverpool with serious injuries. 32 others were treated at hospitals in wirral and chester. there's a multitude of injuries that have happened, but the two patients that have gone through to the major trauma unit at aintree, they have significant injuries. this has clearly been a huge explosion, powerful enough not only to bring down the main building and scatter debris for hundreds of yards, but also to punch huge holes in the walls

of nearby buildings. the emergency services won't speculate on the cause of the blast, but a number of local people said they smelt gas yesterday and on friday. national grid engineers are on the scene. this incident is likely to be protracted, this is likely to last several days. very significant damage, as you can tell. so it will be some time before people will be allowed back into their homes. some people whose homes had to be evacuated spent the night in a local church. nearby roads are likely to be closed for some time. andy gill, bbc news, wirral. 0ur correspondent kevin fitzpatrick joins us now live from the scene. kevin, bring us up to date with what

is going on. well, still huge shock in the area surrounding the side of this blast, you can see behind me where the roof of the dance hall collapsed, the centre point for this explosion. the walls were blasted out, the roof just explosion. the walls were blasted out, the roofjust dropped on top of it, so there is a huge area surrounding it now cordoned off by police as emergency services are on the scene and going through the site. lots of other buildings around it were affected as well, several of them collapsed following the blast. as you mentioned, a chinese restau ra nt as you mentioned, a chinese restaurant was right in the heart of it. i've been speaking to a couple who were sitting at the back of that restau ra nt, who were sitting at the back of that restaurant, and they described the moment when the blast happened. the front windows blasted into the restau ra nt, front windows blasted into the restaurant, everybody was terrified, people were screaming, they thought a bomb had gone off, and people dived under the tables. quite quickly, they realised they had to get out of the building, people were pulling each other out of the rubble, many of them covered in

blood. people still pretty traumatised by what happened last night, and emergency services, with no further update yet on the situation with those who are injured, but two people are injured seriously, more than 30 other people injured as well. many of them still remain in hospital, where they are being treated. 0k, kevin, many thanks, kevin vicars patrick there. let's ta ke thanks, kevin vicars patrick there. let's take a look at the headlines on bbc news. home secretary amber rudd has called on technology firms such as whatsapp to allow security services access to encrypted material in terrorism cases. scotland yard says the westminster attacker khalid masood acted alone and his motive may never be known. detectives confirmed the attack lasted just 82 seconds. more than 30 people have been injured, two seriously, after a suspected gas explosion on merseyside. let's look at the sport now, for a

full round—up from the bbc sport centre, here is john full round—up from the bbc sport centre, here isjohn watson. lewis hamilton believes mercedes have a fight on their hands with ferrari after watching sebastian vettel win the opening race of the formula one championship at the australian grand prix. a badly timed pit stop cost the british driver, as vettel won in melbourne. nick parrot reports. the sebastian vettel victory finger had not been seen for 18 months — until today. that's because mercedes have dominated formula one for the last three years. starting from pole in melbourne, lewis hamilton was the favourite to win the race, and when he emerged from the first corner in the lead, many might have thought all bets were off. new rules have been brought in to make the cars faster, and the sport more exciting, but this race was won thanks to a tactical error. with sebastian vettel pressuring hamilton, mercedes blinked first, bringing him in for fresh tyres. he came out in fifth and got stuck in traffic. radio: we need to get past verstappen. i don't know how you expect me to do that right now! vettel timed his stop to perfection. he came back out

in front of hamilton, and mercedes knew their challenge was over. the german cruised to the chequered flag, winning by more than nine seconds. the last time he won the opening race was in 2011 when he went on to become champion. hamilton has been warned. at the start, i wasn't entirely happy, i think i was too nervous, i had a bit of wheel slip, lewis was better, then i had to take care of valtteri into turn one. but then i was really trying to keep the pressure on to make sure that they get the message, we are here to fight, and i got a bit lucky when lewis came out in traffic. it had been a great weekend for the team, but struggled with the tyres towards the end, i had to stop a lot earlier, i had run out of grip. i was behind one of the red bulls, sometimes the way it goes. but overall, great race, good points for the team, and thank you to this crowd, thank you for coming out, such a great place for us to be.

anthony crolla says he could have no complaints after being outclassed in his bid to regain the wba lightweight title in manchester last night. he lost his rematch withjorge linares on points. in front of a home crowd, he went down in the seventh round after being caught with an uppercut, and although he responded well, linares retained the belt on a unanimous decision. england's ross fisher is out of the world golf championship match play in texas. he lost to japan's hideto tanihara in the quarterfinals, but he did leave with a decent consolation prize — his win over bubba watson in the previous round took fisher into the world's top 50 and earned him a place in the masters next month. scotland beat sweden to take bronze at the world women's curling championship in beijing. skip eve muirhead and her team had lost to the swedes in a play—off yesterday, but they turned the tables, winning 6—4 in the bronze—medal match. canada beat russia to take the gold.

muirhead was delighted with what she called "a really strong team performance", especially with the winter olympics in pyeonchang coming up next year. iam i am looking forward to the olympic games. for great britain, we still have the selection to happen, but we know that great britain has a spot, we have secured a spot in the olympic games, so it is exciting to know that the games is around the corner, but we will keep practising hard, keep training hard so we are even better at the games. for the first time in over 60 years, there are three british players in the finals of the british open squash — and it's down to some great performances. nick matthew beat the world number one, mohamed elshorbagy. at 36, matthew is the oldest finalist in the event since the 1950s. laura massaro came from two games down to beat nour el sherbini in five. massaro, who won this event in 2013, will face sarah—jane perry, who knocked out malaysia's nicol david, who was world number one for nine years. that's all the sport for now. an investigation has been opened

after the pentagon confirmed that american—led coalition fighter jets struck a location in the iraqi city of mosul where many civilians were killed. us central command says iraqi military requested the attack against islamic state militants. tim allman reports. day after day, the exodus from mosul continues. thousands of people have fled the violence as a battle rages for control of the city. plumes of smoke rise above the rooftops, air strikes and shelling taking a heavy toll. now the us military has acknowledged coalition aircraft hit a location in the west of mosul, and it may have been civilians who paid the price. both the iraqi military forces in the us coalition have acknowledged that there was an air strike and possibly hundreds of casualties. we are waiting to see

what the results of the investigation are. we know that there have been many, many families that have been impacted by this tragedy, and that there are a large number of injured, a large number of deaths. in a statement, us central command said... those protected sites as claimed include schools, hospitals, mosques. and sometimes people's homes. this is the neighbourhood where the air strikes happened. eyewitnesses say at least 50 bodies were pulled from the rubble days after the building collapsed. the dead included children, the elderly, pregnant women. thousands have left the city, but thousands more remain. how many more will lose their lives as the battle for mosul continues?

we go to our colleague in your deal, yalda hakim, the situation is confused, but the pentagon is admitting to air strikes in that area, potentially looking very bad. indeed, reeta, for over a week we have been hearing reports that us air strikes have left at least 150 people dead in west mosul. they did issue a statement yesterday, saying they had launched an investigation, that they respect human life, but that they respect human life, but that they respect human life, but that they wouldn't abandon this operation. this is perhaps the most difficult part of phase of this

whole operation for iraqi forces. the front line had now reached the old city, it is densely populated, the streets and alleyways are incredibly narrow, so they will not be able to use tanks, and there will be able to use tanks, and there will bea be able to use tanks, and there will be a lot of street to street fighting, as well as house—to—house tanking. they will also be relying on airstrikes, and tanking. they will also be relying on air strikes, and so it is difficult, in the fog of war, in the murkiness of all this, for us was the bbc to be able to verify a lot of these reports. our middle east editor, jeremy bowen, is in west mosul, and he has spoken to civilians who say that there are ongoing air strikes in the area, that they are very angry about it, but that is militants are also using them as human shields, positioning snipers within their homes, as well as on their rooftops. and, yalda, while attempts are being made to establish what happened and who was responsible, there is a potential humanitarian crisis. indeed, reeta,

yesterday we were at a camp, seeing thousands of people arriving on buses that had been provided by the iraqi army, bringing them out of the war zone. it is very difficult for the civilians — if they stay in west mosul, they risk being killed through air strikes, or from mosul, they risk being killed through air strikes, orfrom hunger. a lot of them have no water, no food, no access to electricity or sanitation. if they try to leave, is snipers may kill them, or they might get caught in the crossfire. when they are brought out, and there are thousands, by 8000 arriving every day at these various camps, there are about 30 or more camps that have been built around northern iraq to keep these people, and the situation there is incredibly desperate for these people. up to a few days ago, these people. up to a few days ago, the weather was quite grim, it was cold and wet, we were being told that people within the area were burning furniture and clothing to keep warm, and when they arrive in

the camp, it is a desperate attempt to get as much food and water for the civilians who are just arriving. yalda, many thanks, our correspondent yalda hakim there. some news from moscow, russian police have detained the opposition leader during a protest in central moscow. he is known as an anti—corruption crusader, and he has previously been detained and been put under house arrest, reuters now saying that alexei navalny has been detained by the police during a protest in central moscow. the labour leader, jeremy corbyn, has said labour will oppose plans to give ministers the powers to change some aspects of european laws, without needing the approval of parliament, when they're incorporated into uk legislation. seaking on peston on sunday, mr corbyn said parliament could not be bypassed on the issue. we need total accountability at every stage of this whole brexit negotiation.

i understand there is going to be about 12 ancillary related bills. we're not going to sit there and hand over power to this government to override parliament, override democracy and just set down a series of diktats for what is going to happen in the future. we'd be failing in our duty as democratically—elected parliamentarians if we did that. police in the us state of ohio say 15 people were shot and one person was killed when at least two men opened fire at a nightclub in the city of cincinnati nightclub. police in the us state of ohio say 15 people were shot and one person they say hundreds of people were in the nightclub at the time, and it was a "horrific situation". however, the authorities do not believe it was a terror attack. at least 18 people have been seriously injured in hong kong after an accident when an escalator malfunction. it was packed with shoppers when it apparently went into reverse at high speed and

dozens into reverse at high speed and d oze ns of into reverse at high speed and dozens of people were thrown to the bottom. one man received a serious head injury. a spokesman for the shopping centre said the escalator at past a recent safety inspection. 0k, at past a recent safety inspection. ok, well, let's take a look at what the weather is doing now with chris fawkes. gloria started the day, fantastic sunrise across the east coast of england, the shepherds don't need to worry about that red sky, they can go back to looking after the sheep, todayis go back to looking after the sheep, today is going to be fantastic. sunshine across the board, early morning mist clearing from the western isles, across shetland quite cloudy, another one—day, temperatures hitting i9 cloudy, another one—day, temperatures hitting 19 degrees across sheltered parts of northern scotland, it could yet be the warmest day of the year so far. overnight, clear skies, another chilly one for northern ireland and rural scotland, but otherwise temperatures staying quite a bit

above freezing. monday, more of the same, local artist of the day across eastern counties of england, burning away with some sunshine. —— low cloud to start the day. 17—18 in the south—east, generally the highest temperatures in the west.