welcome to bbc news, broadcasting to viewers in north america and around the globe. our top stories: 50 years on, commemorating the life and murder of the civil rights leader dr martin luther king. a huge mistake, says mark zuckerberg. he has now admitted data from up to 87 million facebook users may have been misused. china unveils its retaliation in the trade dispute with president trump, but hints that talks are also possible. also in the programme: we meet the south african doctor who gave up medicine to sing his heart out. bells have been tolling in cities

across the united states marking the moment, 50 years ago, that the civil rights leader dr martin luther king was assassinated by a white supremacist. the main commemorative event was at the lorraine motel in memphis, tennessee, where he was shot dead. a bell rang out 39 times, one for each year dr king lived. the civil rights activist jesse jackson is one of only two survivors of dr king's entourage on the day. he spoke from the motel balcony where dr king was shot dead. i've been blessed by god to come back here 50 years later. and every time the scab comes off, the sore is still raw. the blood still oozes. this is the site of the crucifixion. not far from here is the resurrection, the new hope,

and the new possibilities. our correspondent nada tawfik summed up the mood in memphis. i would describe it as almost like a pilgrimage of people young and old, from here in memphis and across the country, coming here not tojust honour the legacy of dr king, but really to recommit themselves to the struggles that he fought against 50 years ago. and so here in memphis, you had 10,000 people marching, you know, in the name of his legacy, singing songs, rejoicing. and here at the official commemoration in memphis there was a mix of performances, and as i say again, celebration, storytelling, from icons who were there with him on that night, and also some very passionate speeches from activists and faith leaders, talking about the opportunity gap that still exists here in america, and all the unfinished business left

to realise dr king's dream. facebook has now revealed that as many as 87 million users may have had their personal information improperly shared with and used by the political consultancy cambridge analytica. that is many more than previously admitted. within the past few hours, chief executive mark zuckerberg has told journalists he had made a huge mistake, and that facebook had not done enough to protect people's information. daniel ives is a cyber security expert with gbh insights in hawaii. he told me mark zuckerberg has a busy few days ahead. he had to do it. i mean, this was something — especially ahead of next week, with the congressional testimony, there's a lot of heat in the kitchen, and zuckerberg's facing it, and this is the first step to calming the waters. do you see this as a kind

of rehearsalfor him giving congressional testimony? i think it's the first step toward next week. it's going to be a grilling he's going to face, and he really needs to come out with transparency. 87 million is a lot bigger than 50 million. and i think this just speaks to now trying to calm the waters, as user and advertising backlash is a major threat to the business model, with regulation the biggest worry. he insists that facebook is not seeing a hit yet, from users quitting or advertisers running. do you believe him? yeah, i mean, look, we believe we're seeing very, very slight backlash. we think at most 2%—3% of users could defect or significantly lower engagement. that could translate to about $5 billion a year of advertising revenue. we think all this is factored into the stock, and now the sorry tour starts next week, as his pr nightmare continues.

he has admitted to a huge mistake. clearly much more data was misused than he has admitted so far. do you suspect there are more revelations to come in this? oh yeah, i mean, look, this is going to be a pandora's box situation, where you're going to continue to see more data come out. i think we'll see more of that next week. so i think it's the tip of the iceberg. but right now it's about trying to calm users, regulators and advertisers, to make sure this won't happen again, and try to make sure the business model stays intact. that's the key. there's going to be some regulation, and now they really need to make sure that this doesn't start a broader chapter that changes the business model of facebook going forward. let's take a look at some of the other stories making the news: president trump is ordering national guard troops to the border with mexico, to protect it, he says, until his promised wall is built. presidents george w bush and barack 0bama both did the same in their time in office.

mr trump has long been keen on a physical barrier along america's southern border. in brazil, supporters and opponents of the former president luiz inacio lula da silva have been protesting, both sides warning of a threat to democracy if a supreme court ruling doesn't go their way. judges are deciding if he can stay out of prison while he appeals a corruption conviction. five out of 11 supreme courtjudges have ruled against him so far, four in favour. he has been seen as favourite to win 0ctober‘s presidential election if his conviction doesn't prevent him standing. the duke of edinburgh has undergone hip replacement surgery at a private hospital in london. in a statement, buckingham palace says the prince, who is 96, is comfortable and in good spirits. saudi arabia will open its first cinema in decades in the next two weeks. it is part of a deal that the saudis have done with amc, the world's largest cinema chain. the plan is to open up to a0 cinemas

in some 15 saudi cities over the next five years. at the hague on wednesday, russia failed in its bid for a joint investigation into the poisoning of a former spy and his daughter. the british government points the finger squarely at moscow for the attack. he said russia's call for such an inquiry was perverse. russia has denied any responsibility. james landale has more. more than one month on in salisbury, the investigation continues into a nerve agent attack that britain believes was carried out by russia. an assessment based on science, yes, but also intelligence. no other country has a combination of the capability, the intent and the motive to carry out such an act. but the head of the porton down military laboratory muddied the waters by saying it was not the job of his scientists to say where the nerve agent had been made, contrary to what the foreign secretary had appeared to suggest. the people from porton down, they were absolutely categorical.

i mean, i asked the guy myself. i said, "are you sure? he said, "there's no doubt." and today, the foreign office deleted an inaccurate tweet that had also suggested porton down had said the novichok was produced in russia. all of which gave russia another chance to question britain's evidence, calling at short notice a meeting of the chemical weapons watchdog, the 0pcw, in the hague, where its diplomats accused britain of a dirty flow of lies and outright russiaphobia. translation: the result of their investigation was announced in a hurry by their prime minister, theresa may, literally a few days after the incident. even though the investigation would take a few weeks or even months. british ministers insisted porton down‘s job was always to identify the nerve agent, and it was for the police and intelligence services

to establish who had used it and why. porton down identified fairly quickly the strain of nerve agent, and once that's identified, you remove from the list of suspects 99.9% of the people. we know that the russians designed it, and we know that the russians were the only people to make it and stockpile it. this muddle is a self—inflicted wound by the british government, that has given russia yet another opportunity to challenge‘s britain's version of events. but for now, at least, the international coalition behind the uk appears to be holding. the eu issued a statement saying it had full confidence in the uk's assessment and investigation, and attacking russia for what it called "a flood of insinuations." and this evening, britain and its allies defeated a russian proposal for a newjoint investigation into the salisbury attack, which mrjohnson branded a "ludicrous proposal to obscure the truth and undermine the 0pcw." but back in the uk, the labour leader accused the foreign secretary

of being too quick to blame russia when he believed other explanations could emerge. borisjohnson seems to have completely exceeded the information that he'd been given, and told the world, in categorical terms, what he believed had happened, and it's not backed up by the evidence he claimed to have got from porton down in the first place. in turn, mrjohnson accused mr corbyn of playing russia's game. 28 countries had backed britain, he said, but mr corbyn had sided with the russian spin machine. so the diplomatic and political fallout from the salisbury attack continues, with russia calling a meeting of the un security council tomorrow. james landale, bbc news. in moscow, the head of russia's foreign intelligence agency has claimed the west is building a new iron curtain. president putin said he hoped common sense would prevail in the dispute over the skripal poisoning. from moscow, our correspondent steve rosenberg. the matinee in moscow seemed an odd choice.

russian bombs at a conference on global security. but the message was loud and clear — that russia is a military superpower and is determined to stand up to the west. when he took the stand, russia's foreign intelligence chief accused the british and american secret services of a grotesque provocation over the salisbury poisoning. the west, he said, was building a new iron curtain. translation: washington has become fixated with the fight against the nonexistent so—called russian threat. this has reached such an absurd level that it's possible to speak of a return to the dark days of the cold war. east—west tension has been building for some time, but the diplomatic war over the nerve agent attack has deepened the divide. this is a situation that is really poisoning our relations, and this is something that we should jointly find an antidote to.

the british are good at creating antidotes, aren't they? and what are the russians creating? chaos, says the west. moscow disagrees. the world according to moscow is a very different world from the one seen through the eyes of the west. russia portrays itself as the cornerstone of global peace and stability, of international order, the very order the british government accuses moscow of undermining through hostile activities. on a visit to turkey today, president putin said he hoped common sense would prevail, not only in the skripal case, but overall in international relations. back at the moscow conference, they may be talking peace and global stability, but business is business. what's the price? it depends on negotiations. whether in arms sales or in geopolitics, russia has set its sights on competing with the west.

steve rosenberg, bbc news, moscow. stay with us on bbc news. still to come: would you like frogs‘ legs with that? these chefs are making the burger uniquely french. 55 years of hatred and rage, as theyjump up on 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

works were beautiful, they were intelligent, and it's a sad loss to everybody who loves art. this is bbc news. the latest headlines: commemorations have been taking place in the united states to mark the assassination, 50 years ago, of the civil rights leader martin luther king. facebook has disclosed that the data of as many as 87 million people — many more than previously admitted — may have been misused by british—based political consultants. now, if anyone thought china would take donald trump's protectionist threats lying down, think again. beijing has announced huge tariffs against us products, day 3 of growing trade tensions that

are spooking financial markets and wiping billions from people's pension plans and investments. robin brant reports from shanghai. in just 2a hours, both the united states and china have laid out plans to hit each other‘s exports. the us has a long list, around 1,300 items, including ovens and flamethrowers. the punishment is in response to claims that china has stolen its intellectual property. it is also about the decades—old policy of forcing foreign firms to share their technology when they invest here in china. china, though, is targeting far fewer products, and it looks like it wants to cause more pain. soy beans, corn, cotton, beef, tobacco are all on the list. soy bean alone is a multibillion—dollar import business to china. these measures would hit specific farming areas of the us hard, but china insists it doesn't want a trade war. translation: frankly speaking,

the challenges we're facing today are huge, for sure, because of the scale of the trade volumes, as you can see. however, china's stance has been clear—cut. we don't want a trade war, because the result will only be a no—win situation that hurts the interests of china, the united states, and the prospect for global economic development. just as significant is the fact that automobiles and aircraft are on the list. ford sells tens of thousands of cars that it ships here from the us, and boeing, the aircraft giant, could see its attempts to make further inroads into the domestic china market put on hold if its aircraft fall into the specific categories being targeted. but all this is yet to be acted on, and there is a possibility of a deal, with the us moving last week to extend its consultation period before acting.

whatever happens now, the reality is that none of these tariffs have yet been imposed, and it appears that the us administration is angling for some kind of negotiated settlement. robin brant, bbc news, shanghai. the retailer sears was once as much a part the american landscape as the rocky mountains. until their business empire started to crumble. the company's ceo said last week that it was fighting to survive, after a merger with rival kmart failed to spark a turnaround. what's happened instead is a tale of an icon in decline, as mat morrison reports. advertisement: put an end to traffic fears, it's very easy to get to sears. sears' appliance spectacular. sears, where america shops for value. it was the american retailer for much of the 20th century, an amazon for its age, sears sold everything under the sun, from homegoods to actual houses. at one time, it was the world's largest retailer in terms of sales, profit and employees.

it was the number — fourth employer in this company. starting as a mail—order watch company, sears branched out to brick and mortar stores — hundreds of them. the heyday of sears occurred right after world war two, that's a period of post—war optimism in this country, and sears followed its customers to the suburbs as they followed their dreams. and then there was the catalogue. the wish book, as they called it, even at christmas time, just became a staple in the american households. three out of four americans shopped or read the sears catalogue. it was what the internet yesterday. you probably know what comes next. sears roebuck, the legendary purveyor by post to rural america, is shutting its mail order business, closing 150 stores and sacking 50,000 staff. decades of overexpansion

and increased competition took their toll, online shopping took off, and the doors started closing. in the mid—1990s, sears had about 3500 retail outlets bearing its name. now, that number is less than 600. sears has been dying such a long death. that may be true but sears itself isn't dead, not yet anyway. they always say had a variety and it was a one place shop, you know, you could come in and get everything. i'm a hands—on person. i, you know, i get books online but everything else, i like to see, touch, try on. i don't do online shopping. my wife, she do all of that but she asks me for the money. many still see france as the home of fine dining — rich food, high—class eating, the occasional glass of wine. but in recent years, fast food has broken into the market. burgers now sell more than ham baguettes. and some french chefs now seem to be feeling if you can't beat them, join them, as the bbc‘s tim allman explains. if you don't like snails, just call them escargot and they'll be magnifique.

when you think french cuisine, this is probably the sort of thing you have in mind — frogs' legs, snails, relaxed, elegant dining. but the french are nothing if not adaptable and they are moving with the times. this is the coupe de france du burger — the french burger cup to you and me — an opportunity for france to say to the us, anything you can do, we can do better. translation: it's true that in everyone's mind, burgers are american. i think it's a beautiful thing to capture your region, capture your culture, with a popular dish like the burger. around 1.5 billion burgers were sold in france last year. the fast food market worth around 51 billion euros, or $63 billion. but these are no ordinary burgers, they come with a gallic twist. translation: by bringing frogs' legs into the ground beef, that's the originality of this burger.

the frog, with green bread to recall the landscape, with swamps and rivers, and it's all made with regional ingredients. the winning chef coming from the southern gard region. his burger comprising walnut bread, locally sourced ground steak, and the finest of condiments — proof that fast food can be french food. tim allman, bbc news. gospel music is wildly popular in most of the world, and nowhere more than south africa. after 10 years of medical practice, dr tumisang makweya decided to devote his time and passion to his first love — singing. he is dr tumi to his devoted fans, and his change of career has proved more successful than he could ever have imagined. good move by dr tumi. to our main story this hour and the commemorations that have been taking place in memphis, tennessee marking 50 years since the assassination of martin luther king. we'll leave you with this musical tribute. # precious lord, take my hand

lead me on, let me stand # i'm tired, i'm weak, i'm lone. # through the storm, through the night. # lead me on to the light # take my hand precious lord. # lead me home. # when the darkness appears and the night draws near. # and the day is past and gone. # guide my feet, hold my hand.

# take my hand precious lord. wednesday brought a real mix of weather across the country. thursday is looking completely different. it's going to be quite a chilly start. frosty start for some of us, but the weather is looking great. so a lot of sunshine eventually in the afternoon. and that'll be right across the country. this is the cloud that's beein bringing the unsettled weather still in the north of the country, snow in places as well. but that is finally clearing away and as we head through the course of the morning, the remnants of the cloud across parts of lincolnshire, the midlands, east anglia, and the south—east but the skies already clearing across many parts of the country. by early on thursday morning, it will turn clear in northern england too, and the temperatures will drop away like a stone across the northern half of the uk.

some rural spots in scotland could get down to —7 degrees, whereas in the south, around 3—6 degrees celsius. so here's the forecast for tomorrow. the last of that cloud clears away from the south—east during the morning and then sunshine all round. however later in the afternoon, the skies might turn hazy out west and into northern ireland. now, a slightly cooler day on the way thursday. maybe 8—12 degrees celsius. that's because the morning will be pretty chilly. that sun will have to work a bit harder to warm things up. you can see there's a weather front approaching. that weather front will be in place across western parts of the uk during the course of friday. quite a split in the weather towards the end of the week. many western areas will eventually turn fairly cloudy. there will be some outbreaks of rain, particularly in plymouth, the western isles as well.

but look at that — central and eastern areas looking sunny. the southerly wind will start to making still warmer. temperatures up to 15 in london, some eastern areas getting up to 13, possibly, as well. now, friday into saturday, that warm air is still kind of with us. certainly not for everybody. it'll be mostly hugging south—eastern and eastern areas of the country. so by the time we get to saturday, the chances are that it may turn a little bit warmer still. however notice that there is a bit of rain drifting out of the south, moving northwards. so some of us will get some rain on saturday, but the possibility of temperatures getting up to around about 17 degrees in east anglia. but for most of us on saturday, it will still be cooler, more like 12—14 degrees. on sunday, eventually that blob of rain from the north will move northwards into scotland. partly cloudy for most of us on sunday. still very decent temperatures, 1a in london, 13 in edinburgh and glasgow as well. this is bbc news. the headlines: bells have been tolling in cities across the united states, marking the moment, fifty years ago, that the civil rights leader

martin luther king, was shot dead by a white supremacist. addressing the crowd by video link, barack 0bama said progress didn't come easily and that people should expect setbacks. mark zuckerberg has insisted he is still the best person to lead facebook, despite the revelation that the personal data of as many as 87 million people may have been misused by british—based political consultants. that's many more than previously disclosed. he admitted making a huge mistake. chadha has responded to the announcement of tariffs on some of its exports by announcing duties of its exports by announcing duties of its own on some american product. —— china. donald trump expressed hope that china would change what he called it is unfair trade practices. it's just gone half past four.