a very warm welcome to bbc news, broadcasting to our viewers in north america and around the globe. i'm mike embley. our top stories: malaysian police say kim jong—nam was killed by the highly toxic chemical nerve agent, vx. iraqi troops make a key breakthrough in the battle for mosul — recapturing the city's airport from the so—called islamic state. historic defeat, britain's main opposition labour party loses a seat they have held for more than eighty years to the governing conservatives in a parliamentary by—election. failed by those who were supposed to protect them — a special report into the widespread sexual abuse of children by un peacekeepers. and a drug bust like no other, how this former nuclear bomb shelter became a den for pot growers. hello.

malaysian police have declared that vx nerve agent — which is rare, restricted, and hugely toxic — was used to murder the half brother of north korea's leader. kimjong nam died shortly after an attack at kuala lumpur airport early last week. it is the first outcome of the postmortem examination that malaysia has made public, and is a strong indication pyongyang was behind the killing. rupert wingfield—hayes is at the hospital where the forensic investigation has been carried out. this is the place we understand kim jong nam's body is being held and where the test that were carried out have revealed the presence of a nerve agent. one expert described this to me as a huge deal for three reasons. firstly, it is a very powerful nerve agent. just 100th of a gram on his skin or i would have been enough to kill him. secondly,

vx is very difficult to produce. that suggests the involvement of a nationstate and points towards north korea. thirdly, vx is a banned chemical weapon under the un chemical weapon under the un chemical weapons convention. that means, if this attack was carried out by north korean agents, they have not just out by north korean agents, they have notjust committed an assassination on foreign soil, but they are responsible for releasing a banned chemical weapon inside a major international airport. i spoke to bruce bennett, a defence and security expert from the rand corporation. he said vx nerve agent is a substance not many people have access to, which reinforces suspicions that north korea might be behind the killing. in fact, it's a nationstate of thing. russia, united states and probably china, north korea, not many other options. which particular nationstate would you say? certainly north korea. they would undoubtedly be the case. how would it have been

handled? how be the case. how would it have been handled 7 how would be the case. how would it have been handled? how would it have been used in an attack such as this? for vx to be lethal to kim jong in an attack such as this? for vx to be lethal to kimjong nam, it would have required about of a gram, less than one drop. it was a part of the water that was on him. vx is an oil, it would not mixed with water. that was a subterfuge, a divergent. it was a subterfuge, a divergent. it was probably in cloth that touched him. just was probably in cloth that touched him.justa was probably in cloth that touched him. just a very small amount touching his skin. over time it would go through his skin and cause the effects we have seen. without being too grisly, what would it have gone to him? he would have been shaking, his nerve system would have been affected, and over time, not very long, he dies. when we were discussing this attack on the first place, there was a lot of confusion as to whyjohn yang would have

chosen to kill him. he had no political ambitions and did not appear to be political ambitions and did not appearto bea political ambitions and did not appear to be a threat? in some of my discussion with north korean refugees, they would say that kim jong nam had killed almost everybody who knew kim jong jong nam had killed almost everybody who knew kimjong nam. he really erased the possibility that he could come in. but what it tells us about kimjong—un, come in. but what it tells us about kim jong—un, his rationality, come in. but what it tells us about kimjong—un, his rationality, and his decisions... —— pyongyang. kimjong—un, his rationality, and his decisions... -- pyongyang. many people would have been in considerable danger having done this as well? they would have been, but if it was only a very small amount ona if it was only a very small amount on a cloth used against him, they we re on a cloth used against him, they were probably relatively safe as long as they did not touch the little area where the drop was. iraqi forces have made a significant breakthrough in their offensive to drive the extremist group,

the so—called islamic state, out of mosul — government troops have regained control of the city's airport. they seized it in hours, against limited resistance from is militants. the airport is strategically important in the battle to recapture the western half of mosul. government forces retook the eastern side across the river tigris last month. quentin somerville has been on the move, with them. before the attack came the air strikes, rockets and artillery. it's day five of the offensive to retake western mosul. slowly, the forces make their way past a suspected is car bomb, talks en route. these armoured columns are now moving forward to mosul airport. the attack of the airport is under way. all night long we've heard coalition aircraft and iraqi artillery slam this area just to the north of us. and in daylight, they didn't let up.

this factory flew the is flag yesterday. today it burned. in less than four hours iraqi forces had breached the airport perimeter, but is fought back. first, the huge roadside bomb. it killed an iraqi officer. despite the air strikes, is fighters were still putting up resistance. the more they advance,

the more difficult it is. they also meet more civilians. they are ina they also meet more civilians. they are in a wretched state. this man says, "they're all dead in iraq. "my brother has already gone to the camp. "he is heartbroken." six of his family were killed in an air strike. this is the last open ground before west mosul. iraqi forces are now less than a mile away. they are also in range of is mortars from inside the city, but the islamic state is under threat. mosul airport may be in ruins, but more importantly it is back in government hands.

over there the iraqi flag is flying on the airfield again. this is a landmark moment. iraqi forces now have the islamic state group on the run. is might transform itself into something else, but right now, here in iraq, we are witnessing the final days of the caliphate. quentin sommerville, bbc news, mosul. mexico's foreign minister has expressed concern and irritation about american policy towards his country. he told the secretary of state that the current us proposals on migration were harmful. mr kelly said there would be no mass deportations of foreign nationals staying illegally in the us. at least eight people have been killed by a bomb in the pakistani

city of lahore. around 30 people were injured in the attack, targeting an upmarket shopping area. there's been a wave of islamist militant bombings in recent weeks, killing at least 130 people. a news conference by france's far—right presidential candidate marine le pen has been interrupted by a semi—naked female protester. the national front leader was outlining herforeign policy when the woman burst into the paris venue — she had "marine fictionalfeminist" scrawled on her back. she was ejected by security. a leading critic of the philippine president, rodrigo duterte, has been arrested on drugs trafficking charges. senator leila de lima was detained by police after an overnight vigil at the senate. just before she was taken away, senator de lima insisted she was innocent and would continue to fight for the truth. here in the uk, the ruling conservative party has won a parliamentary by—election in the north—west english region of copeland. it's the first such gain by a ruling party since 1982. a short time ago i got the reaction from our political correspondent, chris mason in stoke—on—trent. that's what was extraordinary about

the result in the cumbrian district in the north—west of england. the tories gaining a seat, governing conservative party of the uk gaining a seat from the labour party. here in stoke, in the midlands, labour did hold on to a seat they have held since the 1930s. but that is with the uk independence party, a party that was a big advocate of brexit in the eu have done a referendum, they failed to beat labour in this seat, despite about 70% of voters backing the uk leaving the eu —— in. the big question is will be focused in the direction ofjeremy corbyn, the opposition leader of the labour party. a lot of people will recognise ukip as the party that triggered brexit. a lot of questions for them, we were told they were going to break labour in their heartland? their leader, paul

muscles, tried to do that. they failed, despite the fact that so many labour mps have said that jeremy corbyn is not up to the job -- paul jeremy corbyn is not up to the job —— paul nuttall. relief for labour, big questions for ukip. in the copeland seat further to the north, hugejubilation from copeland seat further to the north, huge jubilation from the conservatives. winning a by—election while in government, that is something that happens so rarely. a huge number of questions for labour. very awkward timing forjeremy corbyn. stay with us on bbc news, still to come: police discover a massive haul of cannabis plants in an old nuclear bunker in the english countryside. this is bbc news. the latest headlines: malaysian police have found the highly toxic nerve agent, vx, on the body of the murdered brother of north korea's leader. the presence of vx is a strong indication pyongyang was behind the killing.

iraqi government troops have recaptured mosul‘s airport, a big strategic gain against the extremist group that calls itself islamic state. a task force set up to tackle child sex abuse by un peacekeepers is due to report to member states next week. after a two year investigation, the new head of the un, antonio gutteres, has called for game—changing solutions after a succession of scandals. sexual abuse by some un peacekeepers has blighted the lives of children in many parts of the world — in some incidences they have been accused of raping them in exchange for food. our special report from fergal keane and his cameraman tony fallshaw, from the central african republic, contains some harrowing testimony. this is the story of how international peacekeepers are accused of betraying the trust of some of the world's must vulnerable people. translation: at night it was very cold and the man

offered my son a pill, claiming it would warm him. it took my son five minutes to fall asleep. then the soldier violated him. it's the story of children being abused and of a culture of impunity. injuly 2014, i informed the french government about allegations of french soldiers abusing children in central african republic. nine months after that, i was asked by the un leadership to resign, and when i refused to resign, i was forced out. the scandal began in late 2013 at this refugee camp, an airport runway where french peacekeepers protected thousands of people and their children from violence between rival militias. they and the un helped to prevent genocide. but some are accused

of becoming sexual predators. translation: after the rape, he was crying and afraid, but the soldier reassured him and said not to mention the rape to anyone. their son was 13. they allege the soldier then threatened to stab him if he reported the rape. translation: at first our child tried to avoid us, hardly spending any time at home. when i asked why, he explained what had happened. his friends were mocking him because of the rape. now he takes drugs and won't go to school or socialise with his brothers or sisters. the peacekeeping operation was launched by the french, but it would soon expand into a full un mission. as peacekeepers from other nations were deployed, the allegations of abuse multiplied. senior officials were made aware but they are accused

of failing to act, apart from one brave individual. anders kompass was a senior un human rights official who, in mid—july 2014, was shown an internal report alleging sexual abuse by peacekeepers. i remember i went home and i couldn't sleep during that night because i was struggling with, what is it that i can do? at the un offices in geneva, kompass approached the country whose soldiers were the first to be accused of abuse. he leaked the report to the french, prompting them to start an official investigation. the un was furious, claiming his action potentially endangered children. i was asked to resign for giving this report and the accusation was that i had abused my authority. the alleged abuse continued. a year after anders kompass alerted the authorities, this 14—year—old was approached by a soldier

from the democratic republic of congo. her father was killed in the war and her mother was ill and couldn't feed her children. translation: hunger drove my daughter to see the soldier. she was invited to eat. afterwards... he took her virginity. he gave her money, food rations, and took her to watch videos. the abuse had life altering consequences. the girl became pregnant and was infected with hiv by the soldier. he abandoned her when he went home. there is no hope, no possibility for my children to go to school or my daughter to go to hospital. i suffer constantly thinking about my children's future. it took another month

and the case of this girl, then aged 12, to push the un leadership into action. un troops had raided the family home to arrest a close relative. translation: they started to bang at the door to shout, united nations police, get out of here! she told me there was a man who took her. she showed us the place where it happened. but we found only blood. but this incident and the killing of civilians prompted alarm at un headquarters in new york, after being reported by amnesty international. enough is enough. i cannot put into words how anguished and angered and ashamed i am. the head of mission was sacked,

there was a clamp—down on abuse, and a un report would later harshly criticise senior figures, including the head of human rights on the mission, renner onana. it said he was one of the top figures, whose failure to intervene exposed children to repeated assaults and stated he had helped perpetuate a culture of impunity. but what has happened to renner onana? more than a year after being condemned in the un's own report, he has been promoted and is seen here still working in the central african republic. the un said mr onana would not comment as headquarters was handling the matter. it is understood he rejects the allegations. we did speak with his boss, a respected un veteran, sent in after the scandal. why is he still in the job here? as an organisation, the un has established rules and procedures and in the case of the individual you just mentioned, the staff member you just mentioned, the process is ongoing whereby

he is being allowed to rebut the allegations against him and that process hasn't been completed, as far as i'm aware. do you understand, and you are with the un a long time, how it looks to the people who are critical of this organisation when you have that situation? well, of course. do you? everything that people say about the lack of accountability and bureaucracy? absolutely, i do understand. we have processes and those processes are now being, you know, applied. and it's my strong belief that, at the end of the day the truth will prevail. peacekeepers can only be prosecuted by their own countries and while a whole contingent has since been sent home over allegations, there have only been a handful of charges. after two years of investigation, france hasn't charged any of its soldiers.

it's terrible for the credibility and the trust of the united nations. first of all vis—a—vis the people and the children who have been affected but also to all the people who are inside the united nations because this is a terrible message. the un says new peacekeepers face strict controls. even if there was only one single case left, it would be one case too many. so our goal is zero. it's a familiar un promise. the hopes of the victims depend on it being kept. fergal keane, bbc news, central african republic. just a reminder that there's much more on our website where you can get more background and analaysis on the conflict in the central african republic. just log on to bbc.com/news. president trump's chief strategist has claimed the administration will face a daily battle against what he called

the "corporatist global media". in a rare public appearance — at a conference of conservative activists in maryland — steve bannon said the president's main priority was delivering on his campaign promises — he described mr trump as "maniacally focused on that." he also told the audience they were now the dominant force in right—wing politics. that is why you are seeing executive orders in the supreme court... by the way, the what otherjudges that we will pick, just like they were damp wrong on the case the campaign and just like they'll have a campaign to make damp wrong about the chaos of the transition, they are damp wrong about what is going on today. we have president donald trump fulfilling what it promised the american people and the media needs to understand something— all of this promises will be implemented. thousands of cannabis plants have been discovered by police growing in an underground nuclear bunker

near salisbury in wiltshire. the crop has an estimated street value of more than a million — $1.2 million dollars. six men have been arrested. hidden in the wiltshire countryside, rghq chilmark, a vast underground bunker built to protect britain's leaders in a nuclear war. if we go in here, mind your head. this afternoon, police showed us the vast cannabis growing operation they uncovered here overnight. how would you describe what you have discovered here? a huge, massively professional setup, the biggest cannabis factory farm that i've seen in my 25 years of service. to find this in the heart of rural wiltshire is quite incredible. police found 20 large rooms. each one kitted out with specialist equipment to grow the plants and then dry out the leaves.

officers say huge amounts of power have been secretly siphoned off the national grid. every room has got this setup in it as well. the vents at the top to withdraw all the fumes and take that outside to maintain the heat. in some of the rooms you see signs of people sleeping as well as working. this was the old canteen, still being used last night, it seems, years after the bunker was sold off by the ministry of defence. three people were arrested inside, including a 15—year—old boy. three older men were arrested outside on suspicion of human trafficking offences. in this room police have found hundreds of bags of old compost and they say that suggests this bunker has been used for cultivation for months. it is all very different from when the cold war bunker was last filmed by the bbc. the site had been under surveillance for some time but officers swooped last night when they saw the doors opening. they say local people had reported suspicious activity and a powerful

smell coming from the vents. jon kay, bbc news, wiltshire. to show you some great pictures before we go. a modern—day version of cat and mouse. in this case, the mouth was a drone and the cats, siberian tigers. they were chasing a bird before they spotted the drone that was filming them. it did not ta ke that was filming them. it did not take long before the electronic device became the prey. some cute, yet terrifying pictures, had been ca ptu red yet terrifying pictures, had been captured before it was destroyed. much more on our website. and you can get in touch with me and most of the team on twitter, i'm @bbc mike embley. thursday was a very wild day across the uk.

storm doris packed quite a punch, bringing all sorts of weather — heavy rain, some heavy snow and the damaging gales. you can see a real squeeze on the isobars across the uk leaving off into the north sea into the low countries and denmark as we reached friday. a ridge of high pressure building in. it means that the winds continue to turn light overnight, but with clear skies a new hazard will appear and that's ice across the northern areas. especially where wintry showers continue, so bear that in mind if you are heading out first thing. it will be a much colder night up and down the uk than what we have been used to over the last few nights. it means, however, that into friday things will be fine, thanks to the ridge of high—pressure. it should see plenty of sunshine through the day but it will not stay calm for all areas because later on in the day the next area of low pressure will bring wet and windy weather into northern ireland and then into scotland. but for much of england

and wales it will be chilly. the wind is picking up again across the north of ireland and western scotland. rain becomes heavy and persistent but not reaching the east of scotland until after dark so here you should enjoy the sunshine. rain getting in towards the north—western parts of wales. certainly getting cloudier. the midlands, eastwards, it remains fine. lots of sunshine around. a lovely day with light winds. on the cool side, with temperatures in single figures for most. wet and windy weather across the north—west quarter of the uk. that spreads easterly during friday night, so the wind picks up everywhere. some of the rain will turn to snow over the high ground, we'll see it move across scotland. maybe the far north of england. turning back to rain, as the temperatures begin to rise from the south—west. so a less cold night on friday night than what we will see on thursday. so this weekend it looks like it will be milder. south—westerlies back and it will be windy, certainly across the north and west of the uk.

close to the high pressure it should stay largely dry. you can see the isobars across the uk tightly packed again for saturday. weather fronts crossing the uk. the north—west corner of the country will see the most unsettled weather. wet and windy here through the weekend, whereas the midlands, south—east england, brightness and not a lot of cloud. temperatures in the double figures so back into milder air. on sunday it looks like the south in the east will see the best of any brightness. across the north and west, windy with outbreaks of rain. the latest headlines from bbc news. police in malaysia say they've identified the substance used in the murder of the north korean leader's half brother as vx, an odourless but highly toxic nerve agent. the substance was found on the face of kim jong nam, who died after being attacked last week at kuala lumpur airport. its use is a strong indication that pyongyang was behind the killing.

iraqi troops have recaptured mosul‘s airport, as they continue their attack on the so—called islamic state. iraqi officials say their troops have gained ground rapidly in outlying areas to the south of the city. elite counter—terrorism forces have nowjoined the advance. britain's main opposition labour party has suffered a shock defeat to the governing conservatives in a parliamentary by—election at copeland in the north of england. it's the best by—election performance by a governing party in britain in nearly half a century. now on bbc news, hardtalk welcome to hardtalk. i'm sarah montague.