The World Health Organization has warned against issuing "immunity passports" to people who have been infected with COVID-19 and recovered, saying there is "no evidence" that antibodies protect someone from a second infection.

In Australia, two more cases have brought the national death toll from the coronavirus to 81.

This story was updated throughout Saturday. You can also stay informed with the latest episode of the Coronacast podcast.

This story is no longer being updated. For the latest coronavirus news and updates, follow this story.

Saturday's key moments:

WHO warns against 'immunity passports' declaring people free of COVID-19

The World Health Organization says there is "no evidence" that people who have recovered from COVID-19 and have antibodies are protected from a second coronavirus infection.

In a scientific brief, it warned governments against issuing "immunity passports" or "risk-free certificates" to people who have been infected, saying the practice may actually increase the risk of spread as they may ignore standard advice.

Chile said last week it would begin handing out "health passports" to people deemed to have recovered from the illness.

Once screened to determine if they have developed antibodies to make them immune to the virus, people with the passports could immediately rejoin the workforce.

The WHO said most studies had shown that people who have recovered from infection have antibodies to the virus, but some of them have very low levels of neutralising antibodies in their blood, "suggesting that cellular immunity may also be critical for recovery".

Two deaths in Australia bring COVID-19 toll to 81

Two more Australians have died after testing positive to coronavirus, bringing the nation's death toll to 81.

An 83-year-old man died at Newmarch House aged care facility in western Sydney, the sixth resident to die after contracting COVID-19.

Earlier today, a 90-year-old man from Tasmania's north-west coast was the state's 10th person to die from coronavirus.

Premier Peter Gutwein said in a statement, the man, who was being cared for at the Mersey Community Hospital, died yesterday.

Nine out of the state's COVID-19 deaths have been people from the north-west of the state.

Australia has recorded more than 6,600 cases and 81 deaths from the virus. According to national figures released at 5:00pm, and updated state figures, there were 21 new cases of COVID-19 in the past 24 hours:

New South Wales: 12

New South Wales: Victoria: 3

Victoria: ACT: 2 (local figures attribute one of these cases to yesterday's count)

ACT: (local figures attribute one of these cases to yesterday's count) Tasmania: 3

Tasmania: Western Australia: 1

Sri Lanka reinstates lockdown days after relaxing restrictions, navy sailors among newest cases

Sri Lankan authorities had lifted restrictions, allowing people to gather and pray on the anniversary of last year's Easter Sunday attacks. ( AP: Eranga Jayawardena )

Sri Lanka has reimposed a nationwide 24-hour curfew, after a surge in the number of confirmed coronavirus cases.

The country recorded its highest daily increase in cases on Friday (local time), with 46 new infections.

Sri Lanka has reported 420 COVID-19 cases, including seven deaths.

A month-long lockdown was eased on Monday, allowing people in two thirds of the country to leave their homes during daylight hours.

But the new 24-hour curfew will remain in place until Monday. Police have arrested more than 30,000 people for violating restrictions.

Thirty of the latest cases were navy sailors from a camp on the outskirts of the capital, Colombo, who were hunting those evading quarantine.

The virus is believed to have entered the camp through sailors who were deployed to search for a group of drug addicts who had contact with a COVID-19 patient and were evading quarantine.

A total of 60 sailors have been infected with COVID-19. The camp has gone into isolation.

Trump says he was being 'sarcastic' with disinfectant theory

US President Donald Trump says his widely ridiculed comments about possibly using disinfectant inside people's bodies to fight COVID-19 were sarcastic.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 26 seconds 26 s Donald Trump questions whether disinfectant could be injected to kill coronavirus

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Mr Trump said at a news briefing on Thursday that scientists should explore whether inserting light or disinfectant into the bodies of coronavirus patients might help treat COVID-19, the respiratory illness caused by the virus.

"I see the disinfectant, it knocks it out in a minute, one minute and is there a way we can do something like that by injection inside or almost a cleaning, because you see it gets on the lungs and it does a tremendous number on the lungs," he said.

The following day, Mr Trump sought to walk back those comments while also seeming to continue to advance his theory that disinfectants and sunlight might ultimately help within the body.

"I was asking a question sarcastically to reporters like you just to see what would happen," he said.

The President's comments prompted the maker of Dettol to release a statement saying "under no circumstance should our disinfectant products be administered into the human body".

Australia's Chief Medical Officer Brendan Murphy warned injecting disinfectant could be "quite toxic".

Health professionals have been encouraging people for some time to wash their hands thoroughly with soap or to use hand sanitiser to help stop the spread of the virus.

Videos of the President's comments went viral, attracting thousands of comments and shares on Twitter.

Twitter Inc said the videos did not violate its COVID-19 misinformation policy because the company considered Mr Trump's remarks a wish for a treatment for COVID-19, rather than a literal call for people to inject disinfectant.

The social media site later blocked the trends "InjectDisinfectant" and "InjectingDisinfectant."

US death toll passes 50,000 as Donald Trump signs $750 billion virus relief bill into law

Georgia is among a handful of US states to take the first tentative steps to reopening. ( AP Photo/Ron Harris )

The death toll in the US now exceeds 50,000, according to data from Johns Hopkins University. More than 3,000 of those occurred in the past 24 hours.

The tally of cases in the US now stands at more than 900,000, even as parts of the US reopen after weeks of lockdown.

Gyms, hair salons, tattoo parlours and some other businesses were cleared to open their doors by Georgia Governor Brian Kemp, who disregarded warnings from public health officials that relaxing restrictions could lead to more infections and deaths. Oklahoma, Alaska, and a number of other states have taken steps to reopen as well.

Overnight, President Donald Trump signed a $US484 billion ($758 billion) interim coronavirus bill into law.

The package provides funds to small businesses and hospitals struggling with the economic toll of a pandemic that has thrown a record 26 million out of work, wiping out all of the jobs created during the longest employment boom in US history.

It is the fourth bill passed in the US to address the coronavirus crisis.

Netherlands and Spain death toll continue to rise

The death toll in Netherlands due to Covid-19 is now at 4,409. ( AP: Peter Dejong )

The number of confirmed coronavirus cases in the Netherlands rose by 655 to 37,190, health authorities said, with 120 new deaths.

The country's death toll stands at 4,409, the Netherlands Institute for Public Health (RIVM) said in its daily update.

In Spain, which has been one of the countries hardest hit by the virus, the death toll rose by 378, up slightly on Friday's 367 which was the lowest in a month.

The total of fatalities rose to 22,902 and Spain's Health Ministry said the overall number of coronavirus cases rose to 223,759 from 219,764 the day before.

It came after Spain saw more people being diagnosed as cured than those falling sick for the first time since the outbreak began.

This is partly why Spain has announced it will start easing its lockdown.

Children were trying out their masks in anticipation of their first taste of fresh air since Prime Minister Pedro Sanchez declared a state of emergency on March 14.

The government said under 14s will from Sunday be allowed up to one hour of supervised outdoor activity per day between 9:00am and 9:00pm, staying within 1 kilometre of their home.

World leaders launch WHO COVID-19 plan, but US won't take part

World leaders are set to launch a global initiative to accelerate work on drugs, tests and vaccines against COVID-19. ( Supplied: CSIRO )

French President Emmanuel Macron, German Chancellor Angela Merkel and South African President Cyril Ramaphosa are among dozens of leaders from across the globe who have pledged to help a global initiative to accelerate work to fight COVID-19, the World Health Organization says.

The WHO billed the initiative as a "landmark collaboration" to speed up the development of safe, effective drugs, tests and vaccines to prevent, diagnose and treat COVID-19.

There was one major global power missing from the virtual meeting, however — the US.

"There will be no US official participation," said a spokesperson for the US mission in Geneva.

"We look forward to learning more about this initiative in support of international cooperation to develop a vaccine for COVID-19 as soon as possible."

Mr Macron urged all, namely the US and China, to support the WHO undertaking.

"We will continue now to mobilise all G7 and G20 countries so they get behind this initiative. And I hope we'll manage to reconcile around this joint initiative, both China and the US, because this is about saying: the fight against COVID-19 is a common human good and there should be no division in order to win this battle," Mr Macron said.

US President Donald Trump has lambasted the WHO as being slow to react to the outbreak and being "China-centric", and announced a suspension of funding.

France remains 'vigilant' waiting for second wave

France has extended its stay-at-home order until May 11 in an attempt to slow the spread of the COVID-19 pandemic. ( AP: Michel Euler )

France plans to keep thousands of newly built intensive care units ready for a second wave of virus cases, even though the first wave is receding.

Health authorities said the country doubled its number of intensive care beds to more than 10,000 as the virus raced across the country.

"We need to keep the beds in case of a return of the epidemic," national health agency director Jerome Salomon said.

"We need to maintain a vigilant posture."

There are fewer than 5,000 people in intensive care with the virus.

France has almost 160,000 cases and recorded more than 22,200 deaths from coronavirus.

French authorities said restaurants, bars and cafes would not open before June.

NSW Health Minister scolds beachgoers as state reports slight rise in infections

New South Wales Health Minister Brad Hazzard has reprimanded beachgoers flouting social distancing rules just hours after councils relaxed lockdown rules.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 26 seconds 26 s Coogee Beach crowded on first weekend after reopening

Swathes of people descended on Randwick beaches this morning after the council decided on Friday to limit public beach access to a three-hour window between 6:00am and 9:00am.

"I have to express a degree of disappointment and agitation about the fact that some people, when the rules are relaxed, when we try and do the right thing by giving people the opportunity to have some outside exercise, [they] are disregarding the very strong message of social distancing," he said.

"You've got to stick with the 1.5-metre social distancing.

"It's a sneaky virus, and it could easily cut loose again if people don't stick to the rules."

The warning came as the state recorded a slight rise in coronavirus infections, with 12 new cases since yesterday, including four at the Newmarch House aged care facility in Western Sydney.

Anzac dawn services in driveways across Australia and NZ

Residents in Clara Street, Macleod gather at dawn on Anzac Day in Melbourne. ( AAP: Scott Barbour )

Australians have marked Anzac Day from driveways and verandahs after ceremonies were closed to the public or cancelled due to coronavirus.

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The National Commemorative Dawn Service, with a handful of leaders and veterans present, was broadcast across the country from the Australian War Memorial in Canberra.

Australians were asked to mark the occasion in their driveways with a light.

Prime Minister Scott Morrison, who delivered the commemorative address, spoke of the impact of the coronavirus.

He said it was not the first time Anzac Day traditions had been interrupted and though quieter than usual, it was no less meaningful.

"This year our Anzac Day traditions have been interrupted, but not for the first time," he said.

"On Anzac Day 1919, the first after the Great War, there were no city marches or parades for the returning veterans because Australians were battling the Spanish flu pandemic. Though our streets were empty, they were not forgotten."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 3 minutes 53 seconds 3 m 53 s David Hurley delivers his first Anzac Day message as Governor-General

Usually thousands of people attend dawn services or marches on April 25 in Australia and New Zealand to commemorate the bloody battle at Gallipoli.

New Zealand Prime Minister Jacinda Ardern stood on her driveway with her family.

"This year a new threat faces all nations as the impact of the coronavirus deepens worldwide," Ms Ardern said in a statement.

"As we face these significant challenges, we remember the courage of those who have served in the name of peace and justice."

Plasma trials to begin in Britain

Trials to see if plasma from recovered COVID-19 patients helps fight off the virus in severely ill patients are set to begin. ( AAP: Angela Brkic, file photo )

People who have recovered from COVID-19 in Britain will be asked to be plasma donors to assist in trials to treat ill patients.

The country's health department said up to 5,000 severely ill patients each week could soon be treated with plasma as part of a new approach to treat the virus.

Plasma from recovered COVID-19 patients could assist patients who are struggling to produce their own antibodies to fight the virus, the department said.

So-called convalescent plasma was used as an effective treatment during the 2002 to 2004 SARS outbreak.

"I have every hope this treatment will be a major milestone in our fight against this disease," Britain's Health Minister Matt Hancock said.

There have been more than 144,600 confirmed cases and more than 19,000 deaths from coronavirus in the United Kingdom.

Prisoners armed with weapons demand better conditions in Argentina

Rioting inmates take to a prison rooftop to raise concerns about the lack of preventive measures to stop the spread of coronavirus. ( AP: Natacha Pisarenko )

Prisoners in Argentina have staged protests demanding more hygienic conditions and other measures amid the spread of COVID-19.

Some inmates at Villa Devoto prison in Buenos Aires climbed onto the roof armed with makeshift weapons and set fire to mattresses.

One of the prisoners' banners read "we refuse to die in prison".

Days ago, the country's highest criminal court recommended alternatives to prison for those convicted of minor crimes in a bid to stop the spread of the virus.

Prison protests have taken place in Russia, Indonesia and the US during the pandemic.

Argentina has more than 3,600 confirmed cases and 176 deaths from the virus.

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West Indies and England Test series called off

Organisers are trying to work out when the three-Test series between England and the West Indies can go ahead. ( Reuters: Paul Childs )

The three-Test cricket series between the West Indies and England in June has been postponed due the novel coronavirus outbreak, Cricket West Indies says.

The decision to postpone the tour came as uncertainty continued about the safe resumption of the sport in Britain and international air travel.

Cricket West Indies chief executive Johnny Grave said organisers would be in regular contact to work out when and how the series could be played.

"Clearly playing in June is now not possible and we will continue our discussions with the ECB (England and Wales Cricket Board) and other international boards on trying to find new dates," Mr Grave said.

"We will only travel to England to play the series if our players can be assured that it is safe to do so."

No deaths in South Korea in past 24 hours, officials say

South Korea has conducted an extensive testing campaign and intensive contact tracing to fight the spread of coronavirus. ( Reuters: Kim Kyung-Hoon )

South Korea has reported no new coronavirus deaths in the past 24 hours — the first time that's happened in more than a month.

Only six new cases were reported on Friday.

Officials hope that the number of cases could drop to zero in the coming days.

South Korea has been lauded for its approach to fighting coronavirus, after an outbreak in Daegu saw its numbers soaring.

The country has largely managed to bring it under control without major disruption thanks to an extensive testing campaign and intensive contact tracing, earning praise from the World Health Organization and other nations.

The Government has outlined guidelines for a two-year return to normality, but says it will depend on continued social distancing.

South Korea has a total of 10,718 confirmed cases, with 240 deaths.

Climate activists leave shoes behind as a mark of attendance to protest in Switzerland

Last year was the hottest on record in Europe, according to an EU study released this week. ( Reuters/Arnd Wiegmann )

Green activists placed rows of shoes in central Zurich to mark the place of protesters who normally come out in person each week to demand action on climate change.

Organisers said they wanted to make their point while respecting current restrictions on public gatherings.

A handful of people stood in the background holding banners that read "Wake Up: Climate Action Now" and "Crisis is Crisis" before being dispersed by police without incident.

Greta Thunberg, the activist who founded the global "Fridays for Future" protest movement, acknowledged that demonstrators were having to change tactics.

"Today we had planned a global climate strike with millions taking part. But in an emergency you have to adapt and change your behaviour," she tweeted.

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She said during an Earth Day event earlier this week that countries have a chance to choose a new path as they begin to return to normal after coronavirus lockdowns.

Banned Vienna protest against coronavirus lockdown draws 200

Some Austrians have demonstrated against the coronavirus measures taken by the Austrian Government. ( Reuters: Leonhard Foeger )

A crowd of around 200 defied a police ban to gather in central Vienna for a protest against Austria's coronavirus lockdown.

The restrictions, which have been in place for more than a month, saw bars, restaurants, schools and non-essential shops shut.

Some shops, however, were reopened last week in a first easing of the curbs.

The protest's organisers, the Initiative for Evidence-Based Corona Information (ICI), want the lockdown ended.

They argue, among other things, that wearing face masks and fabric equivalents that are compulsory in shops and on public transport is counter-productive.

After looking on for an hour, police dispersed the crowd, checking the identities of those who stayed. There was one arrest, a spokesman said.

ICI urged people to respect the ban on Friday's event but said it would register "a new, bigger demo" in a week's time.

Austria has reported a total of 15,071 confirmed cases and 536 coronavirus-related deaths.

Belgium signals easing of restrictions

Belgium plans to start easing its coronavirus restrictions from May 4 in a phased reopening during the course of the month.

Restrictions in the country only permit shops selling food, home improvement stores, garden centres and pharmacies to open, with most people only allowed to work from home.

Prime Minister Sophie Wilmes said Belgium could tighten restrictions or delay easing measures depending on the situation.

"It is now time to look to the future," she said.

"But COVID has not disappeared, the virus is still with us and it is dangerous for the population. It is absolutely essential that the safety measures are respected during the phase-out period."

Belgium will need to carry out 25,000 to 30,000 tests a day to withdraw from lockdown, she said.

The step in easing restrictions will include allowing more businesses to open and giving permission to people to meet up with two people not living with them in an outdoor setting.

Belgium has more than 44,000 confirmed COVID-19 cases and almost 7,000 fatalities.

Taliban rejects call for Ramadan ceasefire

The Taliban has refused an Afghanistan Government request to lay down arms in the holy month of Ramadan. ( Reuters, file photo )

The Taliban has rejected the Afghanistan Government's call for a ceasefire during the Muslim holy month of Ramadan to let authorities focus on tackling the coronavirus, raising new concern about prospects for a fragile peace process.

Hopes for an end to Afghanistan's decades of war were raised in late February when the Taliban and the United States struck a deal on the withdrawal of US-led foreign forces in exchange for Taliban security guarantees.

But the deal did not include a ceasefire, which has been left to the US-backed Afghanistan Government to negotiate with the insurgents.

A Taliban spokesman, Suhail Shaheen, said in a post on Twitter that a ceasefire would be possible if the peace process was being implemented "fully" but "hurdles" meant the Taliban would not yet lay down their arms.

President Ashraf Ghani called for the ceasefire for Ramadan and to allow the country to focus on what he said was a critical coronavirus outbreak spreading all over the country.

Afghanistan has detected more than 1,300 cases of the virus but health experts say the number could be higher as testing is limited. There are concerns the country's weak health system would struggle with a widespread outbreak.

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