welcome to bbc news. i'm david eades. our top stories: a blunt warning from the us vice president on a visit to central america — don't come to the united states, because you won't get in. i want to be clear, to the folks in this region who are thinking about making that dangerous trek to the united states—mexico border, do not come. the afp'soperation, ironside, has allowed the afp to make devastating damage to organised crime. today, australia is a

safer country because of afp operations. australian police conduct an unprecedented sting against the criminal underworld, tricking gangsters into using an encrypted communications app. the first new treatment for alzheimer's for nearly 20 years has been approved by us regulators. and the flying boat of venice — could this be the vehicle that helps safeguard the future of the ancient city? welcome to our viewers on pbs in america and around the globe. the us vice president, kamala harris, who's visiting guatemala, has urged its citizens not to come to the united states. this is herfirst stop on a regional tour aimed at tackling the undocumented mass migration to america right at the source.

ms harris and the biden administration are pledging $310 million in immediate humanitarian aid. in addition, there will be long term investments worth $4 billion to boost development and security across the region. and it's notjust money. last week, the us said it would send 1.5 million vaccines doses to guatemala and mexico. but at the same time, one us aid study looking into programmes in guatemala found that from 2006 to 2011, incomes rose less in places that got us funding compared to similar areas that received nothing. and the numbers heading north keep growing. in april, us border agents encountered nearly 180,000 migrants at the border — that's a 20—year high. i want to emphasise that the goal of our work is to help guatemalans find hope at home. at the same time, i want to be

clear to folks in this region who are thinking about making that dangerous trek to the united states—mexico border, do not come. kamala harris�* next stop is mexico city. will grant is there. and i suggested that the vice president's tone had been pretty clear. it is very blunt, and it's not a surprise, no. because we heard the secretary of state make it in costa rica, just a few days prior. it is ultimately the basic tenet of the message from the biden administration, albeit with the subtlety of, look, don't come, because we are going to commit to trying to make conditions better here. the problem they face, of course, is that that has been said by subsequent government administrations in washington, including the 0bama administration, for example. and none of those commitments, those incentives, have really made any great difference to the flow of migration north.

and of course, these particular funds come not necessarily with the caveat, but certainly with the push to anti—corruption efforts and so on, which of course makes the relationship with the governments in question tougher. and she said also the only people who benefit are "coyotes", as she put it. and the message is very much to individuals to — to individuals not to head up to the us border, because they won't get but money is there for a reason, isn't it? and one of those reasons is the governments of guatemala and indeed mexico as well, will find out, no doubt, in the course of her trip, will be expected to do something to slow this down, if not stop it? yeah, absolutely. and i think we know that they have been pushing those governments hard to employ their police, their military to stop the flow of migrants from even leaving the borders of their own country. this is notjust outright

humanitarian aid, this $4 billion package over four years, one of the things bolstered will be security forces. security forces would be expected to disarm and tackle the international drug organisations and criminal organisations that run the drug routes north and the people trafficking routes north. but it would also be to stop, for example, the caravans of people we've seen trying to leave, who have been, you know, stopped from doing so with water cannon and tear gas and so on. you know, this is much more than simply an altruistic measure by the biden administration. will grant willgrant in will grant in mexico as kamala harris makes her way there. a controversial new treatment for alzheimer's has been approved by regulators in the us. aducanumab targets the underlying cause of the disease rather than just easing symptoms. patient groups have campaigned for its approval — but it's a contentious decision — some experts and the federal drug agency's independent advisory committee opposed its approval. 0ur medical editor,

fergus walsh, reports. this is an historic moment in the battle against alzheimer's. for the first time, a drug has been approved which tackles not just the symptoms but the underlying cause of this devastating disease. aducanumab is not yet licensed in the uk and available only as part of a clinical trial — like here, at the national hospitalfor neurology, in central london. aldo ceresa, who's 68, was diagnosed with alzheimer's ten years ago and had to stop working as a surgeon. he receives aducanumab every month, via infusion, and is certain it's helped him. i felt that i wasn't getting so mixed up. my cognitive tests were improving quite markedly. two years ago, aducanumab was written off as a failure and the trial aldo was taking

part in was abandoned. but the manufacturers, biogen, analysed more data and concluded those on the highest doses had better cognition, memory and language. this is the brain of someone with early alzheimer's. the red areas show a build—up of amyloid, a protein which can form toxic deposits. this is the same individual after a year of aducanumab — significant amounts of amyloid have been cleared. so, this drug was approved on the basis of this drop in amyloid that you're seeing here. the doctor who is leading the clinical trials of aducanumab in the uk is delighted. this is a pivotal moment for the alzheimer's research community. this will give hope to the people who haven't had any hope for a very long time.

those patients and participants in my trials who are desperate to find something that helps. in recent years, over 100 promising alzheimer's drugs have flopped, so to now have a medicine that can potentially slow the disease is a huge moment and will encourage scientists to redouble their efforts and find even better treatments. aldo has been back on aducanumab for six months and says he's already beginning to feel the benefits. i've noticed that i'm getting less confused. although it's still there, it's not quite as bad. and i'm just feeling that bit more confident now. aducanumab is suitable only for those with mild alzheimer's, when damage to brain function is still limited. it could take more than a year before uk regulators decide whether to approve the drug. if they do, demand here will be enormous. fergus walsh, bbc news. canadian police are considering charging a 20—year—old man

with terrorism offences, after what they're calling a premeditated attack in the city of london, in ontario. four members of the same muslim family were run down with a car and killed. a boy aged nine, the family's only survivor, remains in hospital with serious injuries. police say it's a hate crime. based on information we collected during the course of the investigation, we believe that this was an intentional act and that the victims of this horrific incident were targeted. we believe the victims were targeted because of their islamic faith. we can cross live to london, ontario, now and speak to mustafa farooq, chief executive of the national council of canadian muslims. mustafa farooq, mustafa fa rooq, thank mustafa farooq, thank you very much forjoining us. i saw the pictures of where the incident took place, there were signs saying, love for all, took place, there were signs saying, love forall, hatred

for none, no heat here. there must be a deep sense of shock, nonetheless, over what has happened? it nonetheless, over what has happened?— happened? it has been incredibly _ happened? it has been incredibly terrifying - happened? it has been incredibly terrifying forj happened? it has been - incredibly terrifying for our community. and i mean, these thingsjust keep community. and i mean, these things just keep happening. both nationally and internationally. i mean, you know, putting aside international issues, here in canada, we had in 2017, an incident and last year, an individual came to a toronto mosque with connections to a white supremacist group, and now this event. it has been a tough few years. do now this event. it has been a tough few years.— tough few years. do you feel yourselves — tough few years. do you feel yourselves more _ tough few years. do you feel yourselves more vulnerable | tough few years. do you feel- yourselves more vulnerable now than you have in recent years? london'smayor was saying they were appalled, and of course, you are a very important and welcome part of the community? i think that obviously, while

we appreciate the messages of condolences nationally and internationally, it is equally important to think and acknowledge that not only does valence and islamophobia and is limo phobic attacks happen across canada regularly, but systemic islamophobia is built into the law here in canada. canada and the province of quebec prevent those who wear the hijab is, for example, from becoming a public school teacher or inferential school boards. that is deeply flawed and problematic ——or in the school boards. d0 and problematic --or in the school boards.— and problematic --or in the school boards. do you have any sense of hepe _ school boards. do you have any sense of hope that _ school boards. do you have any sense of hope that things - school boards. do you have any sense of hope that things will. sense of hope that things will improve? is all for those these incidents are, do they actually serve to impress upon others that situation you are in? i mean, frankly, this was a

family that was lost, full stop. not in the broader sense of what happens in public policy or public opinion, these were four individuals that were taken from this earth. and that is it. right now, we are in shock, our community is broken—hearted. this was a beautiful family. broken—hearted. this was a beautifulfamily. there broken—hearted. this was a beautiful family. there are nine—year—old child is the only remaining survivor. nine-year-old child is the only remaining survivor.— remaining survivor. what else can we say? _ remaining survivor. what else can we say? yeah, _ remaining survivor. what else can we say? yeah, i— remaining survivor. what else can we say? yeah, ithink- remaining survivor. what else can we say? yeah, i think youj can we say? yeah, i think you are right to bring it back to the reality of the situation and the personal pain. mustafa, thank you very much indeed. mustafa farooq.— police in australia say they've made more than 200 arrests in a sophisticated sting operation against organised crime. police were able to monitor encrypted communications because the criminal underworld was using a messaging app that had secretly been developed by the fbi. the australian federal police commissioner explained the global reach

of the operation. 0peration ironside has been enabled by the extraordinarily smart individuals within the afp and law enforcement in 33 countries. globally, today, this operation has seen more than 9000 law enforcement officers deployed to the international effort, and essentially, the long arm of the afp has to get longer so we can keep australians safe at home and develop the next ironside. home and develop the next ironside-— home and develop the next ironside. , ., ., 0ur correspondent, shaimaa khalil, joins us from sydney. a lot of trickery involved, but what they uncovered is just staggering. what they uncovered is 'ust staggeringi what they uncovered is 'ust staggering. the scale of it is . uite staggering. the scale of it is quite remarkable, _ staggering. the scale of it is quite remarkable, and - staggering. the scale of it is quite remarkable, and i- staggering. the scale of it is| quite remarkable, and i think this is why you have heard it being described as a watershed moment in law enforcement history here in australia, and unprecedented operation, because of what they have uncovered and the level of cooperation cross—border cooperation cross—border cooperation between the australian federal police and

the fbi, with three years covert operation there. yes, 9000 officers were involved, 4500 of those were australian, 500 search warrants executed, more than 200 arrests made, 3000 kg of drugs, more than $35 million were seized. a really, really big scale, huge scale operation there. but as you say, it is the trickery, the technology part of it that makes this quite remarkable, david. the fact the fbi and afp were able to trick major figures in the organised crime in australia into using this encrypted application called anom, and intercept and read up to 25 million messages in real—time, open messages, about drug importation, about

execution plans, about mass shootings, many of which were prevented because of this operation now. we prevented because of this operation now.— prevented because of this operation now. we heard the olice operation now. we heard the police commissioner, - operation now. we heard the police commissioner, i - operation now. we heard the| police commissioner, i think, talking about the next ironside. so this is not mission accomplished? it ironside. so this is not mission accomplished? it is not mission accomplished? it is not mission accomplished. - mission accomplished? it is not mission accomplished. i - mission accomplished? it is not mission accomplished. i think, | mission accomplished. i think, you know, a huge part of that mission has been accomplished and that is why they are able to come out publicly, but it was interesting, more questions police had for the commissioner, the more they said we can't give you that much detail, any more detail, because this is still ongoing. this involves the fbi, it involves many other countries, including drug cartels and crime syndicates in asia, the middle east, and europe. it is ongoing. we also interestingly heard the prime minister, scott morrison, seeing more funding and more powers to the federal police are needed for that next phase of, as you say, the next ironside. phase of, as you say, the next ironside-— ironside. indeed. shaimaa khalil in — ironside. indeed. shaimaa khalil in sydney. -

thank you for being with us here on bbc news. still to come: the flying boat of venice. could this be the vehicle that helps to safeguard the future of the city? the day the british liberated the falklands. and by tonight, british troops had begun the task of disarming the enemy. in the heart of the west german capital, this was gorby—mania at its height. the crowd packed to see the man who, for them, has raised great hopes for an end to the division of europe. it happened as the queen moved towards horse guards parade for the start of trooping the colour. gunshots the queen looks worried but recovers quickly.

as long as they'll pay to go and see me, i'll get out. there and kick 'em down the hills. - what does it feel like to be the first man to cross the channel by your own power? it feels pretty neat. it feel marvellous, really. this is bbc world news. the latest headlines: the us vice president — kamala harris — has warned guatemalans against coming to the united states — saying they would be turned back at the border. the first new treatment for alzheimer's for nearly 20 years has been approved by us regulators. with the new academic yearjust months away, universities are sifting through applications to offer places. last year, the us recorded a drop in student visa applications — and this year the number has fallen even further. as sarah toms reports, the pandemic is partly to blame but many students also worry

about rising violence against people of asian descent. singapore student dai xiang rong has always dreamed of studying in the usa. he worked hard and got a coveted place at yale university to take computer science and economics. but the 19—year—old has had second thoughts. for a lot of people, especially asians like myself and my friends, you've seen the recent news of anti—asian racism and attacks, especially in the us and other countries. it's quite a deterrent to our dreams to pursue an international education and it might be because of the pandemic, but beyond that i think there was some sort of racism that was already ingrained in a lot of people's minds. foreign student enrolment at us universities has dropped 16% between the autumn of 2019 and 2020. the stats on new international

students look even grimmer, with a 43% drop. health concerns are a major reason as the us has been hit hard by covid. but racism and violence against ethnic asians are also causing many applicants to pause. some people directly blame the anti—china rhetoric of former us president donald trump. kung flu...kung flu. (crowd cheering). attacks against asians in the us, including the murders of six women in atlanta, have sent shock waves through asia. many asian students are still very willing to study abroad and in spite of the racism, so what they do is they tend to segregate, and they tend to segregate into the ethnic communities, so this will to some extent intensify the racism. to universities, foreign students like these ones here in singapore, bring in plenty of money by paying

higher tuition fees. beyond money, they also bring diversity, fresh ideas, and connections for the future. many experts believe western countries risk losing their competitive edge if foreign students feel unwelcome. missing out on all of that will have repercussions for not only universities but entire economies. as for xiang rong, he is willing to take the risk to pursue his dream. sarah toms, bbc news, singapore. let's get some of the day's other news. police in western india say at least eighteen people have died after a fire swept through a chemical manufacturing plant near the city of pune. most of those killed are said to be women workers. local media reports said those killed in the incident were trapped following an explosion in a machine. airline bosses have called for a uk—us travel corridor to be opened up. nearly all uk passengers are currently banned

from travelling to the us, while any us travellers are required to quarantine in the uk. the airlines say travel between the countries, which have some of the highest levels of vaccination in the world, is "essential to igniting economic recovery". the founder of amazon, jeff bezos, says he and his brother will travel into space next month on his rocket company's first sub—orbital sightseeing trip. a third seat on the spacecraft is being auctioned off. 0ur science correspondent rebecca morelle reports. this is the new shepard rocket. so far, it's only flown with mannequins. now it's ready for its first real passengers, and jeff bezos, who owns the spacecraft, has announced he will be on board, along with his brother. it changes your relationship with this planet, with humanity. it's one earth. i want to go on this flight

because it's a thing i've wanted to do all my life. the rocket system will reach 100 kilometres above the earth, where passengers will experience about three minutes of weightlessness, and see the blackness of space and earth's curved horizon. in the future, anyone will be able to take a ride for around £150,000 a ticket. and it's not the only company to test if space tourism is commercially viable. sir richard branson�*s virgin galactic space plane is expected to carry paying customers by the end of the year. mission control: spacex. separation confirmed. and seats on elon musk�*s spacex capsule cost millions to go into low earth orbit. for now, these trips are only for the super wealthy, but experts say prices should drop. for the young people today particularly, it will become a reality that they could save up some money and choose to go to space, not every day, but it could be something that you could choose to spend a chunk of your savings on, and experience a few

minutes of weightlessness. landing gear deployed. the new shepard flight is due to take place injuly. the capsule carrying jeff bezos and his brother will descend back to earth with parachutes, marking the start of a new era in space tourism. rebecca morelle, bbc news. for the people of venice — life is beginning to get back to normal. most covid restrictions have been eased — and tourists are returning. but venetians face a dilemma — visitors bring money — but too many of them can also endanger the very fabric of the city. the bbc�*s tim allman has more. venice almost seems to defy nature. an ancient city of canals and waterways, its popularity could be its undoing. the sheer number of boats and gondolas can cause erosion.

the constant movement of the water damage in the buildings. this may be a possible solution. a swedish—designed electric boat that its creators insist could make all the difference. here in venice you have a huge problem with wake damage and with our technology when you fly above the canal level of the water level, you reduce that by 95%. who and what travels the waterways of this city is a big issue for the people who live here. only a few days ago there were noisy protests as the first cruise ship to disembark since covid restrictions eased set sail. reducing numbers and reducing speed may helpful but whatever the solution, is a sense that something must be done.

this is an ageing city and we all love venice and if we can help to save it we should. tourist numbers are growing once more. the cafe's and restaurants are seeing more custom. but if venice is to survive perhaps not everything should go back to the way it used to be. if you own a pet there will always be a time when you think you have lost them and usually you have lost them and usually you find them hopefully nearby, perhaps in a park or a garden. this is a bit of a different scenario. look at that poor little thing there. a group of sailors were travelling through the arctic when they found this little dog on a chunk of sea ice in the eyes had started to drift out to sea. they got hold of the pipe and rescued it. they brought it on board and what's more they found the owner. it was in a nearby village who said the dog had in missing for a week. that is one lucky pooch. just to remind you

of our main story, that one mac harris has warned what islands against coming to the united states saying that they will be turned back at the border. hello there. it's been a warm start to the new week. quite a bit of cloud around on monday, but i think certainly for today, it's looking sunnier across the board. it's going to stay warm for the rest of this week, and in fact, we're going to start to import some tropical air across the country, so it's going to feel quite humid. there will be further patchy cloud and rain across northern and western areas, as low pressure will always be nearby. and that's certainly the setup into tuesday, higher pressure to the south, lower pressure to the northwest, so it does mean we'll start off rather grey for much of scotland and northern ireland, through this morning, some patchy, light rain and drizzle. but conditions will start to improve for northern ireland — skies brightening up here and across northeast scotland. elsewhere, after a bit of early cloud and mist, there's going to be a sunny day, and it's going to feel warmer

with more sunshine around. we could see 25 degrees across south east england, 22 or 23 for the northeast of scotland. there could be just the odd shower here and there, but most places will be dry. now, as we head through tuesday night, we'll see further cloud returning to scotland and northern ireland. patchy rain here, some coastal fog, too. further south, and it's drier with clearer skies, and we'll start to see some humid air being imported from the southwest, so everywhere staying in low teens celsius. on wednesday, we'll have high pressure to the south, lower pressure to the northwest with these weather fronts, and the orientation of these pressures will draw up this warm and humid airfrom the tropics, so it really will be quite noticeable on wednesday. again, rather grey across parts of scotland and northern ireland, perhaps western england and wales. best of the sunshine further south and east. could see a little bit of light rain and drizzle over western hills, but it's going to feel warm, particularly when you factor in the humidity. could see highs of 26 degrees on wednesday in the sunshine. if you add the humidity to that, it's going to feel even warmer than the temperatures suggest. thursday's another warm and humid day. perhaps a bit more cloud across the board. patchy rain for northwestern parts of scotland and northern ireland. bit more cloud for england and wales,

but some sunny spells here and there. most places across england and wales should stay dry, but it'll be a bit breezier across the board. windier in the far northwest of scotland, where we'll have most of the rain. but you can see, it is another warm day. low to mid 20s celsius for england and wales. factor in the humidity, of course, it's going to feel warmer than that, and nights are also going to be warm and muggy. could see something a little bit fresher across scotland, northern ireland on friday. otherwise, it's going to remain warm with some sunshine into the weekend.

this is bbc news. i'm david eades. our top stories: us vice president has warned guatemalans against coming to the united states. she said they would be turned back at they would be turned back at the border. speaking during a visit to the countries he said the trip north was extremely dangerous and would mainly people smugglers. the first new treatment for alzheimer's for nearly 20 years has been approved by us regulators. it targets the underlying cause of alzheimer's. it targets the protein that builds up in the brains of alzheimer's patients. the us government says it has managed to recover more than $2 million worth of crypto currency which had been paid to hackers who shut down a major fuel pipeline last month. the colonial pipeline was hacked by a group called dark side.

now it's time for hardtalk.