this is bbc news with the latest headlines for viewers in the uk and around the world. i'm tim willcox. at the trial of derek chauvin, a police trainer tells the court the force used by the ex—officer on george floyd was excessive. a trial of the astrazeneca vaccine on children is paused in the uk while the country's regulator investigates possible links to rare blood clots in adults. russian police detain supporters of the jailed kremlin critic, alexei navalny, amid reports he is suffering from a respiratory illness. this is the prison where he is being held behind these walls. we can't go any further, but he has been getting messages out by his lawyers, and each one, he's been talking about how his

health is deteriorating. the new vountary health is deteriorating. —— the new voluntary one child policy. translation: for me, it's i already hard to raise this one. it feels better to put all your energy into one child, or we might feel guilty that we can't properly take care of many. hello and welcome if you're watching in the uk or around the world. it's day seven in the trial of former police officer derek chauvin in minneapolis, the man accused of killing george floyd by kneeling on his neck in a case that triggered worldwide protests over racial injustice. today, we've been hearing more evidence from former colleagues of derek chauvin in the police department, with a particular focus on the training

that officers receive. larry madowo has been analysing the day's events. we have heard from ten witnesses who are from the police, the minneapolis police department, all testifying that derek chauvin violated department policy, his use of force in the arrest of george floyd was excessive and this is not how they're trained. it is highly unusual to hear that many members of police organisation testify against a member of their own force. there is an unofficial rule called the thin blue line of silence, where police officers often protect their own, which is why it's often so hard to convict a police officer in a case of police brutality or police misconduct as a whole. in this case, they had all come out against officer derek chauvin, who was fired just the day after the death of george floyd. we also heard the first outside witness brought on by the prosecution. he is sergeant from the los angeles police department. he did testify also from the

outside looking in that his use of force was excessive. this is that exchange from the court today. based upon your review of these materials and in light of the ground factors, what is your opinion as to the degree of force used by the defendant on mr floyd on the date in question? my opinion was that the force was excessive. - the reason why this is important is the prosecution is trying to build the case that, as they said in their opening statement, that derek chauvin betrayed his badge, this is not consistent with police training. that is the narrative they've tried to build again and again. and the defence's case is to try to poke holes into that and discredit all the witnesses and to say that these are decisions that officers make that are split—second decisions, and they are situational, they take into account what's happening. in eric nelson's view — he is the lead attorney of derek chauvin — because there were a mob,

there were people yelling and screaming at the officers there, they distracted them, they impaired theirjudgment, and that is why he made those decisions and that is why when he should have turned george floyd on his side so that he could recover, regain breathing. when he should have administered cpr, he didn't do that because of all the other factors around the arrest of george floyd. larry, you talked about the thin blue line. have there been any other trials like this where we have seen police incriminate, in terms of their testimony, fellow officers? it is highly unusual, it rarely happens. the fact that yesterday, the minneapolis police department chief himself took the stand was covered nationally, it was leading the newspapers across the nation because ofjust how unlikely it is to see something like that in trials of police misconduct in america, across the nation. it is precedent—setting and might lead future prosecutors

to call on more police officers to testify against members of the force. here in the uk, a trial of the oxford—astrazeneca vaccine on children has been paused while scientists investigate a possible link with rare blood clots in adults. the university of oxford has told the bbc that there are no safety concerns with the trial itself, but its scientists were waiting for further information. the prime minister boris johnson has urged people to get their vaccination when invited. our medical editor fergus walsh reports. nearly 300 children aged 6—17 are taking part in the astrazeneca vaccine trial in england which began in february. oxford university said there had been no blood clots in the volunteers, but out of an abundance of caution, it had stopped vaccinations, pending the outcome of the safety review in adults. more than 18 million people

in the uk have received the astrazeneca vaccine. the mhra said last week there had been 30 rare cases of blood clots including seven deaths. the prime minister, visiting an astrazeneca plant in macclesfield, once again gave his firm support for the vaccine. the best thing people should do is look at what the mhra say, our independent regulator. that's why we have them, that's why they're independent. and their advice to people is to, you know, keep going out there, get yourjab, get your second jab. as a precautionary measure, the mhra updated its advice last month to say that anyone with a headache that lasted for more than four days after receiving the astrazeneca vaccine or bruising beyond the site of the jab should seek medical attention. both of the vaccines we're using are highly

effective against covid, and the risks of getting sick or dying of covid, for all the people currently being offered first and second doses, are far and away greater than any small theoretical risk that may exist relating to these cases, which are extremely rare. as for the future course of the epidemic here, three academic groups modelling the outbreak all have multiple scenarios showing a third covid wave after a final lifting of restrictions in england in latejune. this model from warwick university looks at the number of patients in hospital with covid, which have been falling fast since a peak injanuary. looking ahead, the assumption is the reopening of shops and outdoor hospitality won't cause major problems for the nhs, but once all restrictions are lifted, a third wave follows, though likely much smaller than previous peaks. but it could be more

or less severe depending on how effective vaccines are at preventing covid and stopping transmission. a seasonal drop in coronavirus could push that third wave well into the autumn. as we start to unlock, i suspect we may see the r number increasing, and we may see another wave. my hope is it will be a somewhat different wave, and we can keep hospital admissions and deaths relatively low. and i think that's the really crucial thing, that if we can do that, then hopefully we are still on track with the road map to release restrictions towards the end ofjune. the astrazeneca vaccine is central to the huge success of the roll—out ofjabs in the uk which is way ahead of the rest of europe. france has restricted the astrazeneca vaccine to adults over 55, germany to those over 60, because of concerns about blood clots in younger adults. the european medicines agency in the uk regulator are due to give updated recommendations

in the next day or two. maintaining public confidence in this highly effective vaccine will be vital. fergus walt�*s reporting —— fergus walt�*s reporting —— fergus walsh. brazil has registered a new daily record of covid—19 deaths on tuesday. the health ministry said 4,195 people died with the virus in the past 2a hours. more than 300,00 brazilians have now died since the start of the pandemic, the second highest total in the world after the united states. the jailed russian opposition activist, alexei navalny, is reported to be suffering symptoms of respiratory illness and fever in the penal colony where he's being imprisoned. he started a hunger strike last week and his health is now worsening. supporters of mr navalny gathered outside the jail earlier today, but several were arrested. our correspondent sarah rainsford has been outside the prison and sent this report.

she came to call for help for russia's most famous prisoner. dr anastasia is a close ally of alexei navalny, and he's complaining of acute pain, demanding to see a medic he can trust. i just want to speak with the chief of this prison. she walked right up to the prison gates. beyond them, the opposition politician's been on hunger strike for six days now. shouting. extra police have been drafted in. every person there, including the press, was captured on camera. this is the prison where alexei navalny�*s being held behind these walls. now, we can't go any further, but he has been getting messages out via his lawyers. and in each one of them, he's been talking about how his health is deteriorating. and his supporters are increasingly worried. i'm really very afraid for his health and his condition. i don't want to let his health

be worse, and ijust... that's why i'm here now. do you trust the prison doctor? no. it was just last summer that vladimir putin's fiercest critic collapsed on a flight from siberia. he was treated in germany, where doctors found traces of a military—grade nerve agent. alexei navalny returned to russia, only to be arrested at the border. but if the kremlin hoped he'd be silenced behind bars, he has defied that. so, last week, state television showed these images of mr navalny. he's in the middle here. it called his complaints of back pain and numbness in his legs "lies and attention seeking". many russians do believe that, and the kremlin�*s claimed that he's a tool of the west. but in the rundown little town where he's now locked up, alexei navalny does

have some supporters. translation: i'm really worried. - really worried for his health, because this is outrageous. he's so sick and they're treating him this way. and this is how they treated dr anastasia. but concern over alexei navalny�*s health won't be dismissed so easily. he has a fever now too, and his prison hunger strike goes on. sarah rainsford, bbc news, pokrov. pro—democracy protesters in myanmar have sprayed red paint on roads and bus stops in the biggest city, yangon. they say it's to symbolise blood on the hands of myanmar�*s military rulers. more than 570 people, including at least 43 children have been killed since the coup on february 1st. but the real number is thought to be much higher. protestors called tuesday their red revolution day — giving them a sense of strength and unity in the ongoing battle for democracy. us ambassador to

myanmar, scot maciel, explains what he thinks the international community needs to do to stop the brutal crimes committed by the military. i think it is really important to call out the military. it's also really important to remember that the military tried to seize power through this coup on february the 1st after it had been soundly defeated, or proxy party was soundly defeated in national elections. and the only son has it, has rejected this coup —— and the nation. i think it's really important that the international community first call out the appalling human rights violations by the military, but also not do anything to convey legitimacy or acceptance of this military regime. or acceptance of this military reaime. �* , .,

regime. but when you were imposed. — regime. but when you were imposed. it _ regime. but when you were imposed, it must _ regime. but when you were imposed, it must have - regime. but when you were | imposed, it must have been clear that the military was involved in all sorts of corruption, extortion they were support... but the world isn't unified, is it? how to stop that, even the threats from the un security council, are blocked by russian and china —— russia and china. blocked by russian and china -- russia and china.— russia and china. true, it is really hard _ russia and china. true, it is really hard to _ russia and china. true, it is really hard to unify - russia and china. true, it is really hard to unify the - russia and china. true, it is i really hard to unify the world. russia and china opposed tougher language in the un security counsel last week. team members are very concerned because i think they recognise not only the human rights problem, but the fact that continued rules by this military raises serious risks of significant indivisibility that can spill over into the region. important as the international response is,

chances are it's going to be what happens inside myanmar that's going to determine where the country goes.— the country goes. sorry, but does the _ the country goes. sorry, but does the world _ the country goes. sorry, but does the world sit _ the country goes. sorry, but does the world sit back - the country goes. sorry, but does the world sit back and | does the world sit back and watch more hundreds, thousands of people get killed because of a repressive state by the military, or does the world actually concentrate on the $30 billion jade sold most years, a lot of the oil, a lot of the other fisheries and other industries that the military take billions of dollars in kickbacks from?- kickbacks from? well, certainly. _ kickbacks from? well, certainly, it _ kickbacks from? well, certainly, it would - kickbacks from? well, certainly, it would be l kickbacks from? well, - certainly, it would be good if the world focused on putting maximum pressure on the military, including by squeezing its sources of revenues. that's what the united states in the uk and the eu and some others are doing, but as you mentioned earlier, not everybody is willing to go that route yet. again, i think part of the problem is that some of these government may

think this is shorter than ordinary coup and they'll have to accept it. i think they don't understand how serious things are getting and what a threat it is to the region if the world doesn't act to put more pressure on the military. stay with us on bbc news, still to come: how less light pollution during lockdown has enabled millions of people to see spectacular views of the sky at night. ..years of hatred and rage as theyjump upon the statue... this funeral became a massive demonstration of black power, the power to influence.

today is about the promise of a bright future, a day when we hope a line can be drawn under the bloody past. i think that picasso's i works were beautiful, they were intelligent and it's a sad loss to everybody - who loves art. this is bbc news. the latest headlines... at the trial of derek chauvin, a police trainer tells the court the force used by the ex—officer on george floyd was excessive. a trial of the astrazeneca vaccine on children is paused in the uk while the country's

regulator investigates possible links to rare blood clots in adults. iranian and american officials are holding talks in vienna, trying to revive the 2015 nuclear deal. the two sides are not meeting face—to—face. instead, they're speaking through european diplomats, who go back and forth between the two parties, hoping to move the conversation forward. the iran deal was meant to ensure that tehran never acquires an atomic weapon. but some world powers don't trust iran, and believe its work on nuclear energy is actually a step towards building a nuclear bomb. iran denies this. so, in 2015, a deal was struck between iran and six other countries. iran would stop nuclear work in return for an end to sanctions. but in 2018, president trump abandoned the deal and re—imposed sanctions on iran, going against advice from european allies, which brings us to today. president biden wants

to rejoin the deal, but both washington and tehran insists that the other side must washington and tehran insist that the other side must make the first move. our correspondent bethany bell has this update from vienna. what they decided today, we understand, is that they've set “p understand, is that they've set up two working groups. one looking at the question of sanctions relief, which is of course i ran�*s big, big concern. in the second looking at the question of what the nuclear question, because iran in response to the us withdrawing from the iran deal has been overstepping the limits that were imposed on its nuclear work, limits that were imposed on its nuclearwork, including nuclear work, including sensitive activities nuclearwork, including sensitive activities like uranium enrichment. and they're going to keep talking about this and see whether they can come to some sort of agreement. everyone says it's going to be very difficult. for decades, china used a one—child—policy to rein

in what the government feared was an ever—growing population which the country couldn't manage. then, in recent years, the rules were eased allowing couples to have two children. there'sjust one problem — most young people don't seem to want to have big families any more. our correspondent stephen mcdonell met some of them in north east china. chinese kids are sometimes called little emperors because parents, limited to one child only, gave their offspring everything. then came the two—child policy, but for many, one has remained well and truly enough. you just have to ask parents with a single child if they want more. translation: i haven't even considered it. - neither emotionally nor financially could i afford it. in china's once prosperous northeast, dwindling populations in many towns have led to a suggestion that this could be the first region to scrap birth limits altogether.

but this may not produce more children. translation: for me, it's i already hard to raise this one. it feels better to put all your energy into one child, or we might feel guilty that we can't properly take care of many. there's been a huge shift in attitude from generation to generation here in china. older generations, they come from big families, and it was a really crucial thing in terms of their lives. but for younger people, it's not the same. they really don't want to have as many kids. it's not as important for them. the one—child policy came into force in the early �*80s to stop an already massive population exploding. later, people in rural areas and those from ethnic

minorities were allowed multiple kids. yet for the vast majority over three decades, having more than one child meant being fined. china in 2021 is a completely different place. young couples want different things. when you look at birth rates throughout history, poverty tends to produce people. that's because every new human being is an extra pair of hands to go to work. then along comes prosperity, and it's not as important to have kids for this reason. another factor is that this huge country has now produced generations of people simply accustomed to small family life. it might be hard to get them to change. stephen mcdonell, bbc news. one unexpected benefit of lockdown has been some truly stunning views of the night sky. according to new research, that's because of a dramatic drop in levels

of light pollution. such a decline can affect human health and wildlife by disturbing biological cycles and behaviours, as our chief environment correspondent justin rowlatt reports. this is what a truly dark sky looks like. billions of stars wheel above the kielder observatory in northumberland. set deep in a forest, the observatory enjoys the darkest skies in england. and, throughout lockdown, senior astronomer dan monk has been filming the incredible views. people often do get emotional when they sit underneath this amazing dark sky and they realise how small they are in the universe. it can actually make people cry, at times. it's estimated 85% of us have never seen a truly dark sky. it means we are missing out because it gives us a sense

of our place in the universe, the awesome vastness of space. but look at this. even a tiny light is enough to extinguish the stars and bring us right back down to earth. the reduction in light pollution this year is an exception. satellite images show the night sky has been getting steadily lighter across the world. changes in light have been linked with obesity, heart disease, depression and even cancer. you see, she's shaking? and some animals suffer even more profoundly. there are such a range of animals which are negatively impacted from this. when you think of our migrating birds, for instance, which are drawn off course by lights. insects, vast numbers of moths drawn to those lights, where they batter themselves to death or where they are predated by bats which change their behaviour to visit those lights, perhaps to their advantage,

but to the deficit of other species of bats. so all of this is happening out there in our night. so what can be done? the good news is we can tackle light pollution relatively easily. small measures like businesses making sure they are turning their lights off at night time when the buildings aren't in use. also, local government making sure that street lamps are properly shaded and the lights targeted, so it's not spilling out there and creating unnecessary light blight. that will mean more of us can see sights like this. justin rowlatt, bbc news, northumberland. a reminder of our top story. on day seven of the trial over the killing of george floyd, more evidence was presented on the training given to police officers. one of the witnesses told the court the former police officer derek chauvin should not have placed his knee on the neck of george floyd.

from me and the team, see you soon. well, the last couple of days have certainly after of days have certainly a cold day comes a cold evening after a cold day comes a cold evening and a frosty night, but here's the good news. over the next two or three days, it's going to turn a little less cold. not mild by any means. in fact, the temperatures will remain below the average into the weekend. but at least we will lose that biting arctic wind. you can see the wind here just from the motion of the clouds. you can see the satellite picture looping, the clouds moving in from the north, so that's where our weather has been coming from. sleep and rain showers and places and that gusty wind, but this is what it looks like there this evening and overnight. largely clear across most of the uk and the winds are dying down too. that current is slipping out into the north sea. —1 or 2 degrees

early on wednesday morning in the south, could be as low as —4 the south, could be as low as “4 or five in the glens of scotland. wednesday is looking something like this. lots of sunshine around in the morning, sparkling and crisp. you'll notice the winds will be lighter. in the afternoon, the weather changes. the winds shift and we get this westerly breeze which will walk in some cloud. we and up with an overcast afternoon. still chilly, four, five six celsius. we start to see a real change in the northwest in the evening. the winds are coming off the atlantic. that means that by early on thursday morning, we're generally frost free. the weather has changed ljy free. the weather has changed by then. no longer do we have the arctic winds from the north. and the reason for it is this weather front which is sweeping to the north. you can see the wind arrows here blowing out of the southwest. fairly cloudy weather across the northwest of the uk on

thursday. some sunshine and you'll definitely notice my milder conditions. temperatures of around 11 degrees in birmingham and london. this slightly milder weather will only be temporary because once this weather front clear through, we open up the doors to another blast, a resurgence of colder air from the arctic. yes, it temporarily turns a little bit milder through thursday and friday, but then come the weekend, it looks as though it's going to turn a bit colder again.

this is bbc news,

the headlines. on day seven of the trial over the killing of george floyd, more evidence was presented on the training given to police officers. one of the witnesses told the court the former police officer derek chauvin should not have placed his knee on the neck of george floyd. a trial of the oxford—astrazeneca covid vaccine on children has stopped giving outjabs while the uk's medicines regulator investigates a possible link with rare blood clots in adults. the uk regulator, insisted the benefits of getting the jab far outweighed the risk. russian police have detained many of the supporters of the opposition activist, alexei navalny, outside the detention centre where he's serving a jail sentence. his doctor was among the people arrested. some of those backing mr navalny say he is suffering from a respiratory illness. now on bbc news. it's time for hardtalk.