hello, i'm tom donkin. welcome to bbc news, broadcasting to viewers in north america and around the globe. our top stories: protests against robert mugabe in zimbabwe ahead of crucial meetings to decide the president's future. a man told me "we want to get in there and tell these people what we think of them". signals from the submarine — argentina believes it's heard from the vessel missing in the south atlantic. it's the annual monarch butterfly migration but this time, mexico is turning conservation into a money—spinner. also in the programme, tributes after the death of malcolm young, co—founder and guitarist of ac/dc — one of the world's greatest ever rock bands. hello and welcome to bbc world news.

tens of thousands of people have marched in the zimbabwean capital, harare, and the second city, bulawayo, calling on their president of four decades to stand down. crowds have been singing at the gates of robert mugabe's official residence, urging him to go. he's been under house arrest since the army took control four days ago. now, the country's ruling party, zanu—pf says it will dismiss mr mugabe as its leader on sunday and reinstate the ousted vice—president. our africa editor fergal keane reports from harare. something happened inside the people today. a shared energy that swept them along the streets. they were there on the big streets and small. a common purpose in a place so long divided. voices that would not have dared speak of robert mugabe a few days ago now sounding his

political requiem. it is a historic moment. it is so special. we have waited for this for 37 years. you have returned from england, you are happy to see this? indeed, i am very happy. this is a new beginning for the people of zimbabwe. what i am seeing here is the death of a dynasty. all of the faces of the nation came into harare. joy was unrestrained and exubera ntly expressed. we watched passing soldiers being enveloped by eager hands and arms. who knows what freedom the military coup will deliver. but an army that was once an instrument of oppression is now celebrated. this tell you everything.

this is what the people feel about the army. it may not last but these are moments where they feel genuine liberation due to the soldiers. fear has been cast off and expectations awakened. watching the march, i met a paramedic with a young family. do you believe that the army will really allow you to be free now? yes, we do. and if they don't? well, it is kinda of difficult for them to stop us because we have been free, just unable to exercise freedoms. those who forced this moment include many who were once ardent supporters of robert mugabe. now they call for the departure of the president and his wife. the people of zimbabwe have spoken and the people of zimbabwe have said "you and your husband should go today and not tomorrow!" robert mugabe is under

intense pressure. yet this afternoon he was refusing to stand down. at one of his official residences, the army was pushing back demonstrators. but they would not leave the area. so people are very angry and they want to get through, past these army lines to this official residence, one of the president's official residences. our man told me that they want to get in there to tell the people what they think of them. the army will remain on the streets and tomorrow the generals will meet president mugabe to tell him that their guns and the sympathies of the people have turned against him. that there is no more time. everyone is now certain that the moment of robert mugabe's departure is growing close. the argentine navy says it has detected signals believed to be from the sanjuan, a submarine that went missing with 44 crew on board.

it last made contact on wednesday. international help from american planes and a british research vessel joined efforts to locate the submarine. argentina's defence ministry says experts are now working to try and trace the source of the calls. here's andrew plant. the san juan submarine, filmed earlier this year at its base near buenos aires. a 2000 ton, 65—metre vessel — a crucial part of the argentine navy since the 1980s. but on wednesday, it seemed to vanish somewhere in the waters of the south atlantic ocean. the submarine left ushuaia, near the southernmost tip of south america, on monday and was heading back to its base in mar del plata, just south of the capital buenos aires — a distance of around 2000km. the search has been concentrated about halfway, the sanjorge gulf, from where the sub last made contact on wednesday. it is a huge area and bad weather

and high waves are now slowing the search. translation: we have to consider that it might be on the surface of the waters, the protocol says, because it would be easier for the submarine to get help that way. the sanjuan has a crew of a 1m. —— the sanjuan has a crew of 1m. it's more than 30 years old but was refitted in 2014. the newest of argentina's three submarines, it carries 22 torpedoes on board. so, what could have happened? the navy said a powerfailure may have caused communication problems. if that's happened, operational guidelines say the submarine should have surfaced. three ships and two aircraft have been searching, nowjoined by a nasa plane, the uk survey vessel hms protector, and a us navy aircraft. now the argentinian ministry of defence say failed satellite calls have been detected, which they believe are from the submarine. it is not clear, though, when the calls were made, why they failed, or whether they

could lead those searching to where the submarine is now. andrew plant, bbc news. let's take a look at some of the other stories making the news. 14 civilians are reported to have been killed in a rebel—held neighbourhood besieged by syrian government forces on the outskirts of damascus. the british—based syrian 0bservatory for human rights said the victims died in airstrikes and shelling in four towns in the eastern ghouta district. syrian state media blamed rebel shelling in damascus. the russian ambassador has dismissed criticism of his country's decision to veto a un security council resolution which would have extended an international inquiry into chemical weapons attacks in syria. this is the 10th time moscow has used its veto powers at the united nations in support of its ally since the start of the conflict. the french—tunisian designer azzedine alaia, whose figure—hugging gowns which helped define the look

of the 1980s, has died. supermodels cindy crawford and naomi campbell have walked the catwalk in his designs, and he had many celebrity clients including former first lady michelle 0bama. the lebanese politician saad hariri is in france where he has confirmed that he will be going back home in the next few days. france has said it is "ready to organise a meeting of the international support group for lebanon". mr hariri announced he was standing down as prime minister while in saudi arabia a fortnight ago. lucy williamson reports. having the president greet you at the elysee palace sends a message. in this case, that saad hariri is still, for france, still the prime minister of lebanon, not a political exile fleeing saudi arabian control. it was a show of support both political and personal. after the meeting, sources said france would continue direct

contacts with the middle east key players. mr hariri said he was finally going home. translation: i will return to beirut in the coming days and will take part in our independence day celebrations. i will make my position known on all subjects after talking to our president. president macron wants france to have greater global influence. 0ld colonial ties to lebanon no doubt played a role in his invitation to saad hariri but he is also stepping into a delicate situation between iran and saudi arabia, two regional powers with conflicting ties to lebanon. saad hariri had been in saudi arabia for two weeks since announcing his surprise resignation, accusing iran and its ally hezbollah of threatening stability in lebanon and saying he feared for his life. the invitation from mr macron to the hariri family

offered a way out of the impasse but not a solution. this was a important meeting but no solution because the solution is among the lebanese, not in france. france can play a role in the middle east between iran and saudi arabia and also, perhaps, between the lebanese but i think the main issue is going to happen in lebanon in the next few weeks. saad hariri left the elysee palace with his family today, having tasted french diplomatic power. he is about to test his own. gerry adams, the leader of the irish republican party, sinn fein, says he plans to stand down next year, after 3a years at the forefront of republican politics. gerry adams was seen as the political voice of the ira at the height of the conflict in northern ireland. he made the announcement at his party's conference in dublin. from there, chris buckler sent this report.

tonight, sinn fein paid tribute to one of the men who built the party. martin mcguinness was a key figure in its divisive leadership. martin was a proud member of the ira. but that was a generation ago. and sinn fein‘s otherfigure, who has been party president for 3.5 decades, announced this evening he would stand down next year. i have complete confidence in the leaders we elected this weekend and the next generation of leaders, and i want to thank everyone who has welcomed me into their homes and communities and made me part of countless campaigns. gerry adams was the leader of sinn fein. but the party was seen primarily as the political face of the ira. and he was a hit figure for unionists who saw him

as an apologist for violence. i have not gone away, you know. but the ira has now gone away. and with a rise in electoral support in the republic, sinn fein‘s new ambition is to be part of government in dublin. if gerry adams is still leader, i don't think so. i think that makes a difference to a lot of people. he is tainted and people believe he was the leader of the ira. he has always denied that. but sinn fein‘s ira past still hangs over the party, both north and south of the irish border. sinn fein‘s new leader, michele 0'neil, has been able to agree a deal to return to power—sharing in stormont, in northern ireland. and there is a challenge for the next generation of leaders here in dublin. in order to go into coalition government, they need to build relationships with parties that have

been keen to distance themselves from sinn fein in the past. nasa says it's launched the first of a new generation of advanced weather satellites which will help to predict natural disasters. the spacecraft has a powerful set of sensors to monitor the earth's surface and atmosphere. nasa says the information, which will be sent to scientists around the world, will help to predict and monitor natural hazards such as hurricanes, droughts, forest fires and rising sea levels. stay with us on bbc world news. still to come: the venezuelan opposition leader, antonio ledezma, arrives in spain after escaping from house arrest in caracas. benazir bhutto has claimed victory in pakistan's general election.

she has asked pakistan's president to name her as prime minister. jackson has been released on bail of $3 million after turning himself in to police in santa barbara. it was the biggest demonstration so far of the fast—growing european anti—nuclear movement. the south african government has announced that it's opening the country's remaining whites—only beaches to people of all races. this will lead to a black—majority government in this country and the destruction of the white civilisation. part of the centuries—old windsor castle, one of the queen's residences, has been consumed by fire for much of the day. 150 firemen have been battling the blaze, which has caused millions of pounds‘ worth of damage. hello i'm tom donkin,

welcome to bbc news, broadcasting to viewers in north america and around the globe. our top stories: protests against robert mugabe in zimbabwe — robert mugabe will meet the military on sunday. fergal keane is in zimbabwe and has been given his assessment on what might likely happen next. basically you have three processes now running in parallel. the people have been on the streets and they have shown their anger to robert mugabe. you have the generals going in to a meeting in the morning telling them again that time is up, and critically his own party is preparing to vote on a motion that would see him expelled.

robert mugabe always said down the years that if people wanted him to go then he would not stand in the way. today, and you can still hear car horns blaring in the background of people angry about the situation, today he got a loud message and that is what he is reflecting on in his official residence across the city tonight. more stories making the news. bangladesh says china has offered to help the skews the ongoing crisis impacting rohingya muslims. more than 600,000 people have fled myanmar since august to escape systematic violence by the burmese armed forces and are living in overcrowded refugee camps. china's foreign minister nitties bangladeshi counterpart on saturday and called for bangladesh and myanmar to resolve the issue through bilateral negotiations instead of international initiative. spain's attorney general, who had a leading role in moves by the spanish state

against catalonian independence — has died suddenly in argentina at the age of 66. spanish prime minister, mariano rajoy, made the announcement of jose manuel maza's death via twitter. after the catalan government declared its independence from spain it was mr maza who announced his office would file charges of rebellion and sedition against the former catalan ministers. the us military‘s top nuclear commander has said he would resist what he considered an illegal order from president trump to launch a nuclear attack. speaking at a security conference in canada, generaljohn hyten, said as head of the us strategic command he provided advice to the president and if he told mr trump the attack was illegal he expected the president would seek a legal option instead. one of the fiercest critics of the venezuelan president nicolas maduro has been speaking out against the country's government. antonio le—dezma has arrived in spain, a day after escaping from house arrest in caracas. pablo 0choa reports. it is an image of defiance that some in venezuela will feel emboldened by.

antonio ledezma, a former mayor of caracas and a staunch critic of president nicolas maduro, now safely in spanish soil after crossing the border into neighbouring colombia. until last week, he was under house arrest, accused in 2015 of plotting a coup to overthrow the government. he spent more than 1000 days in detention and says he will now speak for venezuela's radical prisoners. translation: i will concentrate on travelling the world in exile. i will contribute and be an extension of the hope of the venezuelan people to get rid of this regime, of this dictatorship. venezuela is a victim of a regime that is colluding with drug traffickers. on saturday, mr ledezma was meeting the spanish prime minister who has welcomed venezuela ns critical of their government with open arms. but he says he his not reaching out to madrid to seek asylum,

but political support. translation: i have asked the mr rajoy to continue to encourage the world to put pressure against the tyranny in venezuela. marudo isn't a simply president, he is a tyrant who uses force to control the institutions of the country and seeks to subdue people like me. in caracas, the president was sarcastic, commenting on his politicalfoe's escape. translation: the vampire is flying free in the world. he says he's going to spain to live the high life, drinking wine on the gran via. you can keep the vampire over there. but mr ledezma's saga could re—energise an opposition that has been criticised for not coming up with a plan for venezuela. four months of protest ended earlier this year with more than 130 people dead and no change of government. mr ledezma is now free to become

the most high profile opposition leader, speaking against president maduro outside venezuela. the question remains, how much this will help his supporters inside the country to bring about political change. mexico has officially opened its butterfly biosphere reserve, ready for the migration of monarch butterflies which gather there each autumn, to survive the harsh northern winter. sophia tran—thompson reports. it's travel season and these northerners are looking for a winter escape. every year in autumn, millions of monarch butterflies take the arduous journey to mexico from as far north as canada. some are migrating almost 5000 kilometres. but only a small number survive the journey. to help increase their

chances of making it, a protected check —— statuary is being set up extending across the state of mexico. last year, 200,000 people visited the butterflies. it has changed the landscape and created jobs. translation: the majority of people here were loggers. that was their employment. now we have realised how important the monarch butterflies are so rather than being number is, we now take care of trees. we are replanting forest and protecting them from fires. everything we can. populations of monarch butterflies have decreased significantly over the past two decades. in part because of a decline in native plants but authorities in mexico, canada and the us have stepped up efforts to preserve them and it is hoped this season's migration will be —— will beat last year ‘s with flying colours. a robot in china is narrowing

the gap between man and machine, by not only passing, but excelling in a medical exam against real students. the machine was developed by a university team and researchers say the results show the robot has mastered self—learning and problem—solving. georgina smyth has more. don't before by its friendly appearance. this robot is giving chinese medical student run for their money. the student robot exceeded all expectations when it sat china's national medical licensing examination against half a million chinese students. translation: it scorers 96 points above the acceptance line. this shows it has mastered the medical and clinical knowledge and has the basic ability to employ the knowledge to solve some problems. like any good student, she spent

months studying for the test with research is from the university up loading knowledge from medical books into its brain. but scientists say it is not just into its brain. but scientists say it is notjust a case of memorising content. translation: quite a few questions of case and analysis so you are told the conditions of some patients and some of their symptoms and then you have to tell what disease that is, what treatment should be adopted. many questions are like this. such complicated questions cannot be a nswered complicated questions cannot be answered only by a surgeon. it's essentially a reasoning process based on intelligence. but don't expect this doctor to be treating people any time soon. the robot will be used to assist doctors in clinical diagnosis. malcolm young, co—founder and guitarist of the australian rock band ac/dc has died aged 64. he founded the group in the 1970s with his brother angus, retiring more than a0 years later

to receive treatment for dementia. ac/dc are best known for the albums ‘highway to hell‘ and ‘back in black‘, and were inducted into the rock and roll hall of fame in 2003. tributes have been flowing on twitter for malcolm young. black sabbath frontman ozzy osbourne says he‘s sad to learn of the passing of yet another friend and that he will be sadly missed. god bless. duff mckagan — of guns n roses fame tweets my sincerest condolences going out to the young family today. malcolm young sadly passing too $0011. love ya angus! and eddie van halen says it‘s a sad day in rock and roll. malcolm young was my friend and the heart and soul of ac/dc. i had some of the best times of my life with him on our 1984 european tour. he will be missed. the actor and singer, david cassidy,

is suffering from multiple organ failure at a florida hospital. a spokesman for the 67—year—old, who rose to fame in the 1970s sitcom the partridge family, said he is conscious and surrounded by his family. he was admitted to hospital earlier this week. a new portrait of the queen and prince philip has been released to mark their 70th wedding anniversary. when they were married, then princess elizabeth was 21 years old while her groom was 26. the queen and the duke of edinburgh will mark monday‘s platinum anniversary with a private dinner with friends and family at windsor castle. that‘s it from me and the team. you can stay in touch via twitter. you can get all the stories at our website, bbc .c0 all the stories at our website, bbc .co.uk. hello there.

part two of the weekend will be cold again. a colder start if you are stepping out first thing this morning and it is no surprise that we had a beautiful day across the north. we had clear skies and temperatures have plummeted. in the south, not so clear. we began with dank and grey weather but that gradually eased out of the way. the harshest frost will be in rural areas in northern and eastern parts of the uk but frost is likely elsewhere and it means that it will be a lovely sunny start to the day for most of us. however, where we have had the legacy of damp weather across southern england, parts of wales and those areas more prone to fog, again, if you travel this morning you will hang around at this time of year until the middle of the morning so it will be quite cold and grey. promising across scotland for sunshine. fewer showers and the gale force winds that have been for three days now should begin to ease. that is not to say that it‘s not a cold start.

these towns and cities in the countryside will be below freezing and you will scrape the ice off the cars. fog issues across the southern half of the uk possibly northern ireland, and the weather front is never too far away from the south—west of wales and northern ireland. will tend to topple back into cloud through the afternoon turning skies a little grey that you will feel cold. the wind won‘t be quite so strong in the east, given such a cold start, the temperatures will be lower than they were yesterday. struggling to five or six degrees but not too bad in the sunshine and there should be some around in the late afternoon for watford and west hampshire. they willjust be cold although fine and dry and temperatures will fall away quickly as they will in scotland. cold if you are heading out to any sporting events through the course of the day ahead. through this evening and overnight, we could see snow across the hills of scotland, possibly even at lower levels as we start to see a change. we will watch that for the rush—hour and it may cause disruption. there will be heavy rain for a time before it gets blown away by the brisk westerly wind coming

in off the atlantic. a real change of type and feel i think by the time we reach monday. not necessarily in the north. that cold air really does stagnate and holds on across the north and east of scotland. a question of how far that cold air comes back but at the moment it looks like the mild air will win through for much of the week and could bring with it further rain. severe gale force winds potentially late in the week. this is bbc news. the headlines: two crucial meetings to decide the future of zimbabwe‘s president robert mugabe are due to take place on sunday. army chiefs who seized control of the country on wednesday are expected to push for his resignation. the leaders of the governing zanu—pf party will also discuss his dismissal. the argentine navy says it may have detected signals from the submarine that went missing on wednesday with 44 crew on board. however, the navy said the source

of the calls had yet to be traced. ships and aircraft from argentina, brazil, the us, and the uk have been searching the area where it disappeared. the irish republican leader gerry adams has announced he‘s to step down next year. he‘s spent 3a years as president of the sinn fein party, during which time the republican movement moved from violence to a peace agreement. he has always denied being a member of the ira. now on bbc news, our world. the war crimes judgement in the case of bosnian serb commander,