The World Health Organisation has updated its coronavirus guidance in response to recent research to say everyone should wear face coverings in public where there is a risk of virus transmission.
The change came as Matt Hancock, the health secretary, announced all hospital visitors would have to wear face coverings from 15 June and urged the public to not attend upcoming George Floyd protests due to concerns about the potential for large gatherings to spread Covid-19.
Meanwhile, as the official UK death toll passed 40,000, scientists halted a trial of the anti-malaria drug touted by Donald Trump after researchers at the University of Oxford found hydroxychloroquine was ineffective as a treatment for coronavirus.
Follow the latest developments in the liveblog below:
One of the key developments yesterday in the UK was the decision to make masks mandatory on public transport after 15 June.
Many have questioned why it has taken so long for the measure to be introduced, while the British Medical Association has called for the measure to be extended to other areas where social distancing is difficult.

Face coverings will be mandatory on public transport in England after 15 June, government announces
Exemptions for young children, disabled people and those with breathing difficulties, says transport secretary Grant ShappsPeople will face fines if they refuse to cover their face on public transport, said transport minister Grant Shapps.
He compared the new rule to the alcohol ban introduced on Transport for London a decade ago.
"You won't be able to use public transport unless you are wearing it, so you could be asked to leave and ultimately you could be fined but I don't think that will be necessary in the vast majority of cases," he told BBC Breakfast.
London Mayor Sadiq Khan said the policy would rely a lot on "positive peer pressure" and indicated there would be an "element of discretion and good faith" when it comes to enforcing the wearing of face coverings on public transport.
"The idea is that enough of us wearing these will stop the virus spreading faster," he said.
Mr Khan urged commuters not "take the law into your own hands" if they saw people without face coverings and speak to a member of staff instead.
"I am confident, by and large, that most people will follow the rules voluntarily," he said.

What are the new rules on wearing face coverings on public transport in England?
Young children and those with disabilities or respiratory problems to be exemptA senior official at the government's "world-beating" Test and Trace scheme has admitted it will not be fully operational until September or October.
Ministers have also admitted that the NHS app might not be ready until the end of June.

Test and trace system not expected to be ‘world-class’ until September, leaked comments suggest
Report says senior official admitted service would be ‘imperfect’ and ‘clunky’ at launchLaurence Taylor, deputy assistant commissioner at the Metropolitan Police, warned that future mass gatherings to protest against the death of George Floyd would be "unlawful" due to the current coronavirus restrictions in place.
He told BBC Radio 4's Today programme: "The health protection regulations are really clear that it is unlawful.
"The Government said that for health reasons people should not be meeting in groups of six, so we would strongly encourage people not to come out and gather in these large numbers because they are putting themselves and others at risk.
"And if they do come out, then we would ask them to observe that social distancing, think about those around them.
"But of course, by coming and gathering in these large groups they are potentially risking their health and also risking taking the virus back to their families."
The UK government is facing mounting pressure over its quarantine plans both at home and abroad - with the travel industry leading the protest.
Now several European countries are threatening retaliation towards British visitors unless the 14-day self-isolation scheme is scrapped.
The European Commission is calling on EU member states to lift all border checks within the bloc by the end of June.
French tourism minister Jean-Baptiste Lemoyne said his country would impose a 14-day quarantine on UK visitors if Britain proceeds with its quarantine plan on Monday.
Germany's foreign minister Heiko Maas said he would be "strongly advising" against travel to Britain due to its quarantine. Both countries are set to lift travel restrictions on 15 June.
While the UK and EU continue to see falling numbers of cases and deaths, the outbreak appears to be picking up speed in South America, India and parts of Africa.
India's Health Ministry has reported another record spike in new coronavirus cases — more than 9,800 in the past 24 hours - and a further 273 deaths.
Its number of confirmed cases now stands at 226,770, with 6,348 deaths. The surge in infections is being blamed on the movement of hundreds of thousands of migrant workers from cities and towns to rural areas.
Mexico reported a record daily increase in cases and a further 816 deaths, bringing its totals to 12,545 deaths and 105,680 cases.
South Africa has also seen its largest daily jump in new coronavirus cases, with 3,267, bringing the country's total to 40,792, the highest in Africa.
The total number for the whole continent is now above 163,000.
Brazil now has the third highest death toll in the world after reporting a record 1,437 fatalities on Thursday.
Total deaths in South America's largest nation now stand at 34,021, above Italy and below the United States and the UK.
A further 30,925 cases were also confirmed, according to the health ministry.
Last week the World Health Organisation warned that the region was the new epicentre for the virus.

The Americas are now ‘centre’ of coronavirus pandemic, WHO warns
'Now is not the time for countries to ease restrictions,’ official saysSingapore, which was praised for its early response to the outbreak, now plans to give all of its 5.7 million residents a wearable device that will identify contacts with people infected with coronavirus.
The small device, which can be worn on the end of a lanyard or carried in a handbag, follows glitches with an earlier smartphone-based bluetooth system which limited take up of the technology.
It is hoped the technology will allow the city-state to exit lockdown and restart its economy.
"We are developing and will soon roll out a portable wearable device that will ... not depend on possession of a smartphone," said Vivian Balakrishnan, the minister in charge of the city-state's smart nation initiative said on Friday.
"If this portable device works, we may then distribute it to everyone in Singapore."
The government did not specify whether carrying the device would be mandatory.
Singapore confirmed another 261 coronavirus cases today, bringing its total to 37,183.
The New South Wales state government is taking legal action to stop a Black Lives Matter protest in Sydney on Saturday - on the grounds that it risks an outbreak of coronavirus.
Police had originally approved the protest on the understanding there would be fewer than 500 participants - but thousands are now expected to attend.
"The New South Wales government would never, ever give the green light to thousands of people flagrantly disregarding the health orders," NSW Premier Gladys Berejiklian told reporters in Sydney.
The NSW Supreme Court will hear the matter this afternoon.
Prime minister Scott Morrison has already urged the public not to attend the gathering and similar rallies in Melbourne and other major cities.
Australia has reported low numbers of new Covid-19 cases in recent weeks and has 490 active cases, with just 25 people in hospital.
The average house price fell for the third month in a row in May, according to the Halifax index.
Across the UK, a 0.2 per cent month-on-month decline in property values in May took the average house price to £237,808.
It followed monthly falls of 0.6 per cent in April and 0.3 per cent in March.
However house prices were 2.6 per cent higher compared with a year earlier.
Russell Galley, managing director at Halifax, said: "With the full impact of lockdown measures taking a firm grip on the UK property market by May, the average house price fell by 0.2 per cent to £237,808."
Yesterday the UK reported another 176 deaths, taking the official total to 39,904.
It suggests Britain will pass the 40,000 mark today. The UK has the second highest death toll in the world, behind the US.

UK coronavirus death toll rises by 176 to 39,904
Tally edges closer to 40,000 markWorkers at Israel's main airport went on strike to demand compensation for wages lost due to the coronavirus crisis.
Ben Gurion Airport, near Tel Aviv, put about 2,500 airport workers on unpaid leave in early March and is currently only handling a small number of daily passenger and cargo services.
The workers' strike, which would have affect 37 flights on Friday, including 17 outbound and 20 inbound, was called off after a few hours following a request for negotiation from Israeli transportation minister Miri Regev.
"The workers that were placed on unpaid leave have now stopped receiving unemployment benefits. We need the government to find a solution," said Gali Gabbay, spokesperson for the Israel Airports Authority's workers' union.
Russia has reported another 8,726 cases of coronavirus, pushing the total number of infections to 449,834 - the third highest in the world.
Officials said 144 people had died in the last 24 hours, bringing the official nationwide death toll to 5,528.
Willie Walsh, head of International Airlines Group, has told Sky News that no final decisions have been taken about redundancies at British Airways.
BA plans to make up to 12,000 of its 42,000 staff redundant, and to change the employment conditions of those who keep their jobs. It blames the collapse of demand created by the coronavirus pandemic.
He said: "We are facing the greatest crisis the industry has ever seen."
IAG is the parent company of British Airways, and also runs Aer Lingus, Iberia and Vueling.
Willie Wash said that IAG, parent company of British Airways, may try to challenge the UK government's quarantine plan in court.
He said there had been no consultation with the industry prior to the legislation being brought in, and that the new rules would "torpedo" the airline's chances of flying in July.
"We think it is irrational, we think it is disproportionate and we are giving consideration to a legal challenge to this legislation," Walsh said.
British Airways was not able to apply for state aid, unlike other airlines in Europe, he added.
He said they were instead relying on a £300m loan from the Bank of England.
The Office for National Statistics (ONS) has released figures on how many people at any given time are infected with Covid-19 across England.
It said: "At any given time between May 17 and May 30, we estimated that an average of 0.10 per cent of the community population had Covid-19.
"This equates to an average of 53,000 people in England.
"Modelling of the trend over time shows evidence that the number of people in England testing positive has decreased in recent weeks.
"There were an estimated 39,000 new Covid-19 infections per week in England between April 26 and May 30, equating to an incidence rate per week of 0.07 new cases per 100 people."
New analysis from the Office for National Statistics (ONS) has found that 28 per cent of excess deaths registered between March 7 and May 1 in England and Wales did not involve coronavirus - a total of 12,900 deaths out of 46,380.
Excess deaths refers to the number of deaths that is above the average total for this period in the previous five years.
The non-Covid-19 excess deaths identified by the ONS have occurred mainly in older age groups, particularly for frail elderly people with underlying health conditions.
The ONS said that "undiagnosed Covid-19 could help explain the rise in these deaths".
Turkish president Recep Tayyip Erdogan has cancelled the weekend curfew planned for 6/7 June following a public backlash.
He said the measure was announced to reduce the spread of the disease after a rise in the number of cases.
"The evaluations we received from our citizens led us to reconsider the decision," Mr Erdogan announced on Twitter.