this is bbc news. i'm duncan golestani. our top stories: the french president describes a police officer who swapped himself for a hostage during a supermarket siege as a ‘hero‘. 3 people die — the attacker is shot dead, and the policeman remains in hospital fighting for his life. british officials search the london headquarters of the firm at the centre of the privacy row involving facebook data. the head of porton down military research centre dismisses russian suggestions it might have leaked the salisbury nerve agent. and it's back to school for prince harry and meghan markle on a visit to northern ireland. welcome to the programme. security forces in southern france have shot dead a man claiming

allegiance to the islamic state group, after he killed at least three people and wounded 16 others in separate locations. the french president, emmanuel macron, says it was another terror attack on his country. he's praised the heroism of a police officer, who swapped himself for some hostages during a siege at a supermarket. lucy williamson reports. it wasn't a symbol that was attacked in trebes today. a local supermarket provided the only target necessary — people. special forces surrounded this provincial branch after a gunman burst in, shouting his allegiance to the jihadist group islamic state. translation: people were running everywhere. lots of them were wounded on the ground. our butcher was shot. translation: i took cover, but he saw me, he ran after me. i don't know if he had run out of bullets. i managed to escape through an emergency exit.

the gunman was named as 26—year—old moroccan—born redouane lakdim, known to police as a petty drug dealer, but not a violentjihadist. his motive the release of salah abdeslam, a key suspect in the november 2015 paris attacks, currently in jail in france. lakdim began by hijacking a car in carcassonne, killing a passenger and injuring its driver. then he shot and wounded a policeman — the bullet, passing three centimetres from his victim's heart. before heading to trebes, where he took several people hostage inside the supermarket, shooting two of them dead. with hundreds of police surrounding the building, one senior officer swapped himself for some of the hostages. unknown to the attacker, his mobile phone was connected to his colleagues, listening outside. when lakdim began firing at him, special forces stormed the building and shot the gunman dead.

the officer is now fighting for his life. france's interior minister, visiting the scene, called him a hero. president macron said he did honour to his office and his country, and that france had once again been the victim of islamist terrorism. translation: i invite all citizens to be aware of the seriousness of the terrorist threat. but also understand the strength and resilience of our people who have been attacked. tonight, police have raided the flat in carcassonne where redouane lakdim lived. one close associate has been taken into custody. this investigation, raising old unanswered questions about how to spot everyone at risk of radicalisation, and how to tackle a threat that strikes at random in every corner of france. the president said attacks of chains

—— changed. where the risk was originally from syria and iraq, there are now dangerous individuals inside france. the challenge is how to spot them and tackle a threat that strikes at random in every corner of france. and for more on the french supermarket siege, head to our website. you'll also find plenty of background information on the gendarme being hailed as a hero, after volunteering to take the place of a hostage — that's all at bbc.com/news. let's take a look at some of the other stories making the news. the us attorney general has announced plans to change gun laws which will effectively ban bump stocks. the devices can modify a semi—automatic rifle to fire like a machine gun. the move is a response to last october's mass shooting by a gunman at a hotel in las vegas, which left 58 people dead and more than 800 injured.

iran has condemned the appointment by president trump ofjohn bolton as his new national security advisor. in the past, mr bolton has advocated military action against both iran and north korea. five catalan separatists, including a presidential candidate, have been detained by spain's supreme court pending their trial for a crime of rebellion. among those detained wasjordi turull, who is campaigning to lead the region. if found guilty at trial they could face up to 30 years in prison. tens of thousands of people have demonstrated in cities across poland against plans to further tighten the country's already strict abortion laws. a draft bill before parliament would outlaw abortion on grounds of foetal abnormality and would only allow terminations in cases of rape or incest. a search operation is continuing

at the london offices of cambridge analytica, the company at the centre of the facebook data privacy scandal. the british information commissioner is investigating allegations that the firm illegally harvested personal data from fifty—million facebook users to influence the last us presidential election. lebo diseko reports a search of cambridge analytica. 18 enforcement officers working for the uk's information commissioner looking to documents, computers and anything else relating to information gained from the profiles of facebook users. this is where it all began, a british academic invented an app which invited facebook users to do a personality test. 300,000 downloaded it and it

collected personal information on them and all of their facebook friends, passing on data from 50 million users. that dato was obtained by the consultancy cambridge analytica in 2014 and it says it deleted that information but it's been claimed it was used by the firm in its work for the compilation campaign, an allegation it strenuously denies. it's called the meaty —— the media frenzy distressing and says, we in no way represent the politically motivated and unethical company some have sought to portray. but the questions for both facebook and cambridge analytica remain. facebook says it is made changes to stop data breaches in future but britain's information commissioner wants to know whether personal. was gained in unauthorised way, if there was enough consent to share at and what was done to safeguard information. its part, cambridge analytica says it is committed to helping investigation. the director of britain's

military research laboratory at porton down has dismissed russian suggestions that his facility was the source of the nerve agent that left a former russian spy and his daughter in a critical condition. scientists at the chemical defence unit have been analysing samples taken after the attack on sergei and yulia skripal in salisbury. our security correspondent, gordon corera, was given special access to porton down and sent this report. it is one of the most sensitive and a secret sites in the country. porton down, home to the defence science and technology lab, and now the heart of the salisbury poisoning investigation. inside one of the labs, scientists demonstrated to us one of the many ways used to detect the presence of chemical agents. a call came here to porton down in the early hours of monday, march 5, and within hours as specialist response team was deployed down the road to salisbury. they collected samples which report back to labs here at the site, and which

identified a military grade nerve agent. based on that as well as other information, government has said it is highly likely that russia was responsible for poisoning sergei skripal and his daughter. security at porton down is tight. russian diplomats have raised questions as to whether somehow nerve agent from here could have got out. that is something officials say is impossible. we have the highest levels of controls of security around the work that we do here. we would not allowed to operate if we had lack of control that could result in anything leaving the four walls of our facility here. so we have got complete confidence that there is nothing that could have come from here into the wider world. frustrating when you hear that kind of accusation? it's a coincidence that it's down the road but this has happened, it is frustrating to hear that because everyone here knows

it is not true. they emphasise that their work here is purely defensive. chemical agents are pumped into this chamber to test how well chemical suits given to soldiers stand up. there have been allegations in russia that a new chemical weapons factory is being built, but officials showed us the local planning application saying what is being built here is actually going to be a facility for the analysis of explosives. what about the accusations that there is a secret local warfare facility being built here? that is just nonsense, this is a defensive organisation and we know that the russians have been suggesting certain buildings are making chemical warfare, and that is just complete rubbish. this afternoon the park bench in salisbury where sergei and yulia skripal were found were taken away. found was taken away. international inspectors from the ocpw are now taking samples from the scene.

they are also working inside porton down itself to independently confirm its analysis, gordon carera, bbc news, porton down. public health authorities have issued new advice for members of the public who were in the two locations visited by sergei and yulia skripal on the days surrounding the attack. duncan kennedy is in salisbury. you will remember just you will rememberjust over two weeks ago public health england were telling people who have been to the restau ra nt telling people who have been to the restaurant and the pub to wash their clothes, take them to the dryclean 01’ clothes, take them to the dryclean or bag them. they have hardened up that advice and say if people had gone to those two establishments and you haven't washed your clothes, you should do so immediately and that is the word they used and the people with dry—cleaning, don't take it to the dry cleaner, call the council, they will come and take those clothes away and destroy them. that is the advice being given. people

will be compensated. they say while there is no immediate health risk, it is possible but unlikely that any substance that has come into contact with clothing or belongings could still be presents in minute amounts and therefore contaminate your skin. even though we are nearly three weeks into this incident, public health england are still advising people about how to deal with this if they are in those establishments. duncan kennedy reporting there from salisbury. well, european union leaders meeting in brussels said they're preparing co—ordinated measures against russia over the salisbury attack. in separate talks, they agreed guidelines for the next phase of the brexit negotiations, which will focus on trade and security. with more on that, here's our political editor laura kuenssberg. they don't always look so pleased to see each other. the eu's chief negotiator grasping the prime minister's hand. today, the day when formally, finally, the stage right after brexit, the transition, was agreed.

i welcome the fact that the eu council this morning has agreed the details of the implementation period. this gives certainty to people and businesses. it gives them the clarity to plan for the future. i believe we are approaching this with a spirit of cooperation, a spirit of opportunity for the future as well. not much will change for nearly two years after we leave, but how closely will the uk hug the continent after? that is the next fight on the table, the next details to work out. time is of the essence, the eu's most powerful voice said. if the uk wants to leave the customs union and the single market, that means a free trade agreement, germany's angela merkel said. agreeing a buffer zone between leaving the eu and cutting off all ties was never in doubt today. but theresa may's argument also swayed eu leaders to turn up

the pressure on russia. the union even pulling back its own ambassador here to brussels. perhaps, after months of difficulties, britain's stock here is on the up. it's notjust the eu ambassador leaving moscow. other european countries say they will send russian diplomats back there, in coordinated moves next week. but leaders here have been willing to walk the walk alongside britain. matching theresa may's stance. in contrast to an awkward pause yesterday. the european union agrees with the uk government assessment that it is highly likely that the russian federation is responsible for this attack and that there is no other plausible explanation.

despite the tough brexit negotiations, the european union has demonstrated unanimous and unequivocal unity with the uk in the face of this attack. we decided to call back our european ambassador in moscow. this is an extraordinary measure, we never took it before. this time, although the uk is leaving the eu, the continent still stands together. the next 12 months could fray those alliances. then she will make this departure for the final time. stay with us on bbc news — still to come: meeting the dapchi girls freed from captivity. nigeria's president pledges the return of all those still held by boko haram. let there be no more wars or bloodshed between arabs and israelis. i'm very proud of you both.

with great regret, the committee have decided that south africa should be excluded from the 1970 competition. chanting. streaking across the sky, the white—hot wreckage from mir drew gasps from onlookers on fiji. woman: wow! this is bbc news. the latest headlines: a police officer who swapped

himself for a hostage in a supermarket siege in france is in a critical condition in hospital. the 25—year—old gunman who said he'd been acting on behalf of the islamic state group — killed three people in separate attacks before he was shot dead. officers from the uk information watchdog have been searching the headquarters of the firm at the centre of the privacy row involving facebook data. president trump has signed a massive government funding bill into law, just hours before the third government shutdown of the year was due to start. earlier, he'd tweeted that he was unhappy with aspects of the bill and threatened to veto it. as a matter of national security i have signed this omnibus budget bill. there are a lot of things that i'm unhappy about in this bill, there are a lot of things that we should not have had in this bill, but we were, in a sense, forced if we want to build our

military, we were forced to have. there are some things that we should have in the bill but i say to congress, i will never sign another bill like this again. i not going to do it again. i'm not going to do it again. at least fifteen people are reported to have been killed, and many more injured in a suicide attack in the afghan province of helmand. the explosion took place at a sports event in the town of laskar gah. harvey biggs reports. the aftermath of a deadly car bomb attack in afghanistan's helmand province. they vehicle packed with explosives blew up outside a sports stadium in lashkar gah as spectators were leaving a wrestling match. authorities say the bomber tried to go inside the stadium mf""“’ fwf—tfff’ ’