this is bbc world news. i'm kasia madera. our top stories: the terror threat level in the uk is raised after an explosion hits a morning rush—hour commuter train in london. it's the fifth terror attack in the uk this year. the so—called islamic state group says that one of its "detachments" planted the device. the un meets to discuss north korea's latest missile launch and calls the launch "highly provocative". and cassini ends its 20 year mission by heading directly for saturn before burning—up in the planet's atmosphere. hello and welcome to bbc world news. the uk terror threat has been increased to critical, the highest level, meaning an attack may be imminent. it's in the wake of a bomb explosion on a rush—hour train in london.

british police say they are treating the explosion as a terrorist incident. 29 people were injured. so—called islamic state says it carried out the attack. it happened in the morning rush hour as a district line train pulled into the station at parsons green in south—west london, the bbc understands that the bomb, described as a homemade device, had been fitted with a timer. but it failed to fully detonate. whoever planted it, is still on the run. on the floor of the tube, still in flames, it was supposed to blow up the carriage. that bag is on fire. it caused panic, fear, some injuries, but thankfully it didn't kill. guys, let's get away and move to the end of the platform. at 8:20am, this train, packed with commuters, had just arrived at parsons green.

it was loud enough to make me wonder what the bang was, and i looked round and this wall of fire was just coming towards us. i turned left and i saw the fireball surge towards my side. luke walmsley was in the carriage listening to music. a bang and then a flash to my left. almost immediately, sort of a surge of people screaming and running towards me. the improvised bomb was in a white bucket, with wires attached, in a lidl freezer bag. david nelson saw it partially detonate. within minutes, armed police, fire crews and ambulances arrived. it was clear there were some injuries. no—one allowed through here. burns and, from the stampede after, nearly 30 taken to hospital. this woman's commute to work ending in a very different way. relieved to be safe.

a large area around parsons green tube station has been cordoned off and this afternoon the police announced they were evacuating local residents living closest to it, to allow them to try and make that device left on the train a bit more stable. as so—called islamic state said it carried out this terror attack, the police hunted the would—be bomber and the terror threat level to the uk was raised. the joint terrorism analysis centre, the independent organisation which is responsible for setting the threat level on the basis of available intelligence, has now decided to raise the national threat level from severe to critical. this means that their assessment is that a further attack may be imminent. the army will now replace police officers at some locations, as hundreds of detectives search for who planted this bomb. this is a very complex investigation

which is contining at speed with the full weight of the london counterterrorism policing resources assisted by colleagues from around the country and our intelligence agency partners, such as mi5. for those who walked out of the tube carriage today, there is, of course, relief. but with a bomber on the run and fears that another attack could be imminent, these are tense times for those whose job it is to catch him. lucy manning, bbc news, parsons green. the bomb is being examined by forensic teams and officers are looking through cctv at the station for clues about who planted it. our security correspondent gordon corera reports. the device at the heart of the investigation. the ongoing hunt for the person who planted has now lead to the uk's threat level moving up to critical. its highest level. the makeshift bomb will have yielded

some clues in that hunt. like these wires coming from the bucket, used to try and trigger an explosion. they look similar to these christmas tree lights that a birmingham man planned to use in a home—made device before he was arrested. such improvised devices do not always go off properly. that was the case on july 21st, 2005. experts believe today's bomb also didn't explode as intended. the size of the device that was employed was quite significant. and had that device functioned in its intended and designed mode, we'd have seen considerable casualties. many people injured and probably many people killed. the explosive may have been a compound called tatp. this footage from brussels airport and metro shows the devastation when it detonates properly, more than 30 were killed. it's also thought to have been used

in the manchester arena attack this year. that involved a suicide bomber. but today's attacker wanted to get away and used a timer. that is similar to damon smith, seen here leaving a timed device at north greenwich a year ago, which was spotted before it went off. today, hundreds of counterterrorism detectives have been deployed in this investigation. they've been forensically analysing this device, looking for fingerprints and dna. they've also been scouring cctv images, looking for an individual carrying this bag onto the tube and then getting off without it. that will have been the starting point for their manhunt. mi5 are helping the investigation. they will want to know if the individual was part of a group or acted alone and, as has often been the case recently, if they were previously known to authorities. unfortunately it would not be a surprise and this concept of a lone wolf now would more

accurately be described as a known wolf. increasingly attacks, when they happen, have been committed by individuals who were known in some way to either the counterterrorism police or mi5 beforehand. 0fficials here have reacted with irritation to this tweet from donald trump: theresa may responded that it was never helpful to speculate about an ongoing investigation. for the fifth time this year, the country is dealing with the aftermath of a terrorist attack. and tonight, with no sign yet of an arrest, officials felt they had to raise the threat level amid fears the danger has not yet passed. you can keep up—to—date with the manhunt in london, following the parsons green attack, by going to our website where there is also more eyewitness accounts and analysis.

just click on our website bbc.com/news, or download the bbc news app. let's take a look at some of the other stories making the news. hundreds of protestors have been blocking streets of the us city of st louis in missouri. they are protesting against the acquittal of former cop jason stockley, who is white, from a murder charge following the 2011 shooting of anthony lamar smith, who was black. more than 500 protesters marched chanting "no justice, no peace" and some held black lives matter signs. the parliament of iraq's autonomous kurdish region has voted to go ahead with a controversial referendum on independence in ten days time. the country's central government in baghdad, which is very much against any move that might lead to the kurdish area breaking away, says the referendum is unconstitutional. the prime minister of iceland has

called for a snap election after a party quit the coalition government over a judicial scandal. prime minister bjarni benediktsson said he preferred the election to be held in november, almost a year after the last snap vote which was triggered by the panama papers scandal. north korean leader kimjong—un says his final goal is to establish equilibrium of real force with united states, after test firing of a missile over japan early on friday. the united nations security council described the test as "highly provocative". it's the second time north korea has test fired a missile overjapan. it travelled 3,700 kilometres past the island of hokkaido and landed in the pacific ocean. rupert wingfield hayes reports from niigata, in japan. siren wails in northern japan, friday began with this very unpleasant wake—up call.

speakers blared out warnings. commuters were cleared from railway stations, and trains halted. that's a nice wake—up call. foreign tourists were left bemused by what was going on. far above, a north korean missile was flying past. this behind me is the sea ofjapan. we've come up from tokyo because this is the place that is most affected. this is the place where this morning they were woken up by those sirens and by that message that a north korean missile was flying overhead. for the people who live here in towns and cities along this coast, it is the second time that has happened in less than three weeks. this afternoon, we found this man playing with his young daughters and fretting about how to protect them. translation: i want to protect my kids but we don't have a basement. we have nowhere to hide.

the missile takes only ten minutes to reach japan. what can we do in ten minutes? erica told me she is frustrated by japan's refusal to talk to north korea. translation: the sirens, to scare people, there's nothing you can do. so what is the point? the government needs to have a real policy. it needs to talk to north korea. this is the type of missile that is thought to have been fired. it flew further than any north korean rocket has ever gone before. in tokyo, prime minister shinzo abe marched out to face the cameras again. "if it continues down this road", he said, "north korea will have a dark future". but his words have an increasingly hollow ring. beneath this house, one person has taken matters into his own hands. behind a heavy steel door,

seichiro ishimoto takes me into his own nuclear bunker. translation: since these missile launches began, i've had so many calls about the air filtration system. i've had at least 800 enquiries this year. mr nishimoto is safe in his bunker, but the rest of japan is wondering what it can do, and when the next missile launch will come. rupert wingfield—hayes, bbc news, niigata, northern japan. its not only north korea's neighbours who are concerned about this latest launch. in new york, the united nations security council held a special session. it's already met this week to step up sanctions against pyongyang following a nuclear test on september 3rd. the united states wants china to do even more. but as our china editor carrie gracie explains, it's difficult for china to pressurise north korea as much as us wants it to.

iam in i am in north—east china never north korean border, as you say, and it is an area where they remember with pride the korean war. memorials like the one behind me, which they call a war against the united states to assist korea, and that gives you some sense of the difficulties they face, that historical memory, economic reasons, strategic reasons, and reasons of sheer self—preservation against a vengeful north korean dictator. all those reasons holding back from abandoning the north korean regime absolutely. so they've been trying to hold the position as you see again today with their defensive response to american pressure, formal acute factions against north korea. they say, we are implementing the existing resolutions to the letter at enormous economic cost ourselves. all sides need to ratchet down the

tensions, according to china. at at the end of the day, with every provocative north korean move missile test, nuclear test, provocative north korean move missile test, nucleartest, china provocative north korean move missile test, nuclear test, china is coming under increasing pressure. the ground beneath it is shrinking not just the ground beneath it is shrinking notjust internationally but at home, because the chinese public is increasingly concerned about the nuclear threat and china's foreign policy experts increasingly say north korea is strategically a liability and not an asset. we arejust we are just getting a line from the chinese ambassador to washington from the reuters news agency. the chinese ambassador to washington says china will never accept north korea as a nuclear weapons state. so categorically the chinese ambassador to washington says china will never accept north korea as a nuclear weapons state. the line just coming to us from the reuters news agency and adding that china is ready to

implement un resolutions against north korea. so a few lines, from the chinese ambassador to washington, saying the us should refrain, also adding from issuing threats over north korea, do more to assume dialogue and negotiations. so lots of different lines coming through. our correspondent nick bryant in new york says the us took a less aggressive tone than usual in the un security council meeting. especially from donald trump, the president, none of the fire and fury rhetoric we heard in the summer, none of the locked and loaded tweets. in fact, none of the locked and loaded tweets. infact, he none of the locked and loaded tweets. in fact, he has not engaged in anyform tweets. in fact, he has not engaged in any form of digitised sabre rattling on his twitter feed today. nor has the trump administration called for fresh sanctions. we seem to make fresh sets of sanctions passed at the security council in

the past month, and the trump administration is saying today that those sanctions should be given time to ta ke those sanctions should be given time to take effect. but american patients clearly is running thin. sanctions have not worked before, and the national security adviser hr mcmaster today said we can't keep kicking this came down the road, because we have run out of road and we have run out of time. he said, be under no illusions, there is a military option. although he did say that the trump administration's preference for now was not to use it. now, next week at united nations, world leaders will be gathering here for the annual un general assembly. north korea will be very high on the agenda. donald trump will be here, but his chinese counterpart won't be, and i think that reduces the chances of a diplomatic breakthrough. stay with us on bbc news. lots more to come on the programme.

freedom itself was attacked this morning, and freedom will be defended. the united states will hunt down and punish those responsible. bishop tutu now becomes spiritual leader of 100,000 anglicans here — of the blacks in soweto township, as well as the whites, in their rich suburbs. we say to you today, in a loud and a clear voice, enough of blood and tears — enough! translation: the difficult decision we reached together was one that required great and exceptional courage. it's an exodus of up to 60,000 people, caused by the uneven pace of political change in eastern europe. iam free! this is bbc news.

the latest headlines: the terror threat level in the uk is raised after an explosion hits a morning rush—hour commuter train in london. the un meets to discuss north korea's latest missile launch, and calls the launch highly provocative. united nations human rights experts are extremely worried about the arrest of an egyptian lawyer who was detained as he was about to fly to switzerland to meet them. the lawyer, ibrahim metwaly, was due to speak to the un working group on enforced disappearances about cases including that of giulio rejenee , the italian doctoral student who was tortured to death in egypt. from cairo, orla guerin reports. lawyer ibrahim metwaly, who dared to fight for egypt's disappeared,

including his eldest son. last sunday, at cairo airport, he disappeared himself. he wound up here at the high security prison complex, instead of addressing un experts in geneva. now, the lawyer is facing charges of illegally founding an organisation for families of the disappeared. his younger son, also a campaigner, told me he knew the risks, but he wanted to speak for the disappeared, like the murdered italian giulio regeni. translation: my father actually expected that he might be stopped at the airport, but he chose not to let fear control him. he took the risk to bring the voice of the victims, to bring the voice of the victims, to the end, to the entire world. your brother has disappeared, your father is now behind bars. are you

worried that you could be next? translation: i am living with this fear. it is difficult, but history will remember that i did something. human rights groups say as many as 1300 people have disappeared off the streets in egypt over the past two yea rs, streets in egypt over the past two years, taken streets in egypt over the past two years, ta ken by streets in egypt over the past two years, taken by the military or national security agencies. they say most reappear weeks or months later in custody, having been tortured. last year, the italian research giulio regeni was tortured to death after he vanished in cairo. egyptian authorities denied involvement, but rome recalled its ambassador. though there has been nojustice for regenl there has been nojustice for regeni, a new italian ambassador has just arrived here. human rights campaigners say that sends the wrong message to the egyptian government.

it has already changed. just by announcing that the ambassador is coming back to egypt, we had a website blocks, we had members in arrested, and the government feels entitled to do whatever it wants. how serious could the consequences be? i think the plan for the government is to silence anybody who speaks out on enforced disappearances. we asked egypt's interior ministry for an interviewer or comment about forced disappearances. it didn't respond, but in the past, the ministry has said there is no such thing in egypt, not a single case, and any allegations to the contrary are part ofa allegations to the contrary are part of a propaganda campaign against the government. now, for 13 years it has been sending home some of the most remarkable images of saturn. but earlier today, cassini's mission came to an end, when the space probe plunged into the planet's atmosphere. during its epicjourney, cassini documented extraordinary discoveries and gave us new insight

into this mysterious planet. our science editor david shukman has more. it has been a journey that sounds like something from science fiction, nasa conjuring up animations of the cassini spacecraft flying around the spectacular rings of saturn. but this really did happen, and these are some of the images the mission actually captured. the planet seen from closer than ever before. the strange detail of its rings. a jetstream in the shape of a hexagon. and an utterly weird collection of moons. but today, the expedition had to come to an end. i'm going to call this the end of mission. at mission control, in california, hugs and applause. for many, it has been the work of a lifetime, and no surprise there were very mixed feelings as the final signal reached earth.

well, it's been a part of my life for 20 years. we've spent day in and day out thinking about cassini, planning the observations, focusing on the science. my career has been based on cassini, so it's really hard to see that go. saturn is the most distant world to have been explored for so long. and the cassini spacecraft, which is almost as big as a bus, has achieved something never attempted before. it has given us unprecedented views, and these have led to dozens of discoveries. the mission is described as one of the most remarkable journeys of exploration, while it has been orbiting saturn for a staggering 13 years. now, it is one of saturn's moons, called enceladus, that has produced the most startling revelation. plumes of vapour were spotted blasting out of it. now, this turned out to be water. so let's take a closer look inside what we now know, that under a covering

of ice, there is an ocean. and scientists have come to an amazing conclusion — that in here there is every ingredient needed for life. this opens up a whole new realm of possibilities in the search for life beyond earth. and the discovery of conditions on moons like enceladus is a real breakthrough for scientists like linda spilker, who started her career at nasa three decades ago, when the mission began. we wanted to know, is there life on enceladus's ocean? could there be oceans inside of other moons? it will take future missions to go back and answer those questions. the mission captured these images of saturn's moon titan, and this is the sound the spacecraft recorded. to make sure cassini didn't contaminate any of the worlds where there may be life, it was sent to its destruction. but it has raised some tantalising new questions. david shukman, bbc news.

the sad news that cult american actor harry dean stanton has died aged 91. in a career of over 60 yea rs, aged 91. in a career of over 60 years, he appeared in films including alien and godfather two. he often played loners and offbeat characters. he was also a talented musician, paying guitar and harmonica and singing with a tenor voice. he served in the us navy in the second world war and fought in the second world war and fought in the battle of okinawa. he died peacefully at cedars—sinai hospital in los angeles. don't forget you can get in touch with me and some of the team on twitter. i'm @bbckasiamadera. hello. after several days of quite

cool hello. after several days of quite cool, showery weather, only subtle changes taking place this weekend. there will be fewer showers around by the time we get to sunday. throughout the weekend, occasional sunshine. it feels quite pleasant in the showers, it feels quite cold, some quite chilly nights around as well. perhaps a touch of frost and a few places. it is chilly because there has been a flow of air from there has been a flow of air from the north. high pressure to the west of us, low pressure to the east. the aircoming down of us, low pressure to the east. the air coming down from the north of these pressure systems is unstable air, bringing showers. a few of the showers for western parts of wales, connell, devon, a few near its north sea coast zones, into northern scotla nd sea coast zones, into northern scotland as well. but away from the showery areas, and most of us will be away from the showery areas, we are likely to start the day with some pleasant sunshine. some areas are and there, but where you have been clear for are and there, but where you have been clearfor any are and there, but where you have been clear for any period of time

overnight, it will be a chilly start, temperatures are only gradually recovering as we go through the morning. it is still on the breezy site. you will certainly notice that across northern scotland, and here we are getting a fair few showers scotland, and here we are getting a fairfew showers coming in on scotland, and here we are getting a fair few showers coming in on that stiff breeze. so on through the day, then, where you start with some sunshine, the cloud is going to build. there will be the threat of a shower. where you start cloudy, you may well see the sunshine come out for a may well see the sunshine come out fora time, may well see the sunshine come out for a time, but there is still the threat of a shower. it could be we see a longer spell of rain moving into parts of western scotland and into parts of western scotland and into northern ireland. the showers get going elsewhere. there could be some heavy downpours around, especially in eastern parts of england, that could come with a rumble of thunder but everywhere at risk of getting at least one shower moving through, that may be heavy. temperatures into the mid—teens. as we go on through into the evening, the chance again for a spell of rain. this time for south—west england. and even overnight, saturday night into sunday, there

could be some heavy rain for some in the south—west england. heavy showers close to the south coast, whereas many other places will become dry. and it is going to be much cooler in rural spots compared with towns and city centres. for some, in scotland, maybe northern ireland as well, we'll get close to freezing for a touch of frost is sunday begins. maybe one or two mist and fog patches, because there are lighter winds on sunday. as high pressure begins to nudgee and it will give mainly dry weather to scotland, northern ireland variable cloud. wales and western england will see relatively few showers, but elsewhere across england, a scattering of showers. there could be on the heavy side, but by no means will everyone get one. with lighter winds, more seeing some sunshine, it will feel a little bit warmer by the time we get to sunday. at monday and tuesday is looking pretty quiet. not many showers at all. quite a bit of cloud, a little bit of sunshine. this is bbc news. the headlines: the terror threat level in the uk has been raised from severe to critical after a explosion on a tube train. the so—called islamic state group

says that one of its so—called "detachments" planted the device. the un has called north korea's latest missile launch ‘highly provocative' and called on pyongyang to denuclearise the region. the united states, china and russia have all condemned the missile test. amnesty international says it has new evidence which shows an "orchestrated campaign" by security forces to burn rohingya villages in western myanmar. it claims it has evidence the military is trying to push the rohingya out of the country. the american actor harry dean stanton has died at the age of 91. in a career that lasted over 60 years, stanton appeared in films including paris, texas, cool hand luke and godfather 2. now on bbc news: inside out.