Fidel Castro, who defied 10 US presidents in his 50 year rule, dies aged 90

Beijing, May 24: The Chinese virology institute in the city where COVID-19 first emerged has three live strains of bat coronavirus on-site, but none match the new contagion wreaking chaos across the world, its director has said.

Scientists think COVID-19 -- which first emerged in Wuhan and has killed some 340,000 people worldwide -- originated in bats and could have been transmitted to people via another mammal.

But the director of the Wuhan Institute of Virology told state broadcaster CGTN that claims made by US President Donald Trump and others that the virus could have leaked from the facility were "pure fabrication".

"Now we have three strains of live viruses... But their highest similarity to SARS-CoV-2 only reaches 79.8 percent," she said, referring to the coronavirus strain that causes COVID-19.

US demands immediate start to WHO review

The United States called on the World Health Organisation on Friday to begin working immediately on investigating the source of the novel coronavirus, as well as its handling of the response to the pandemic.

One of their research teams, led by Professor Shi Zhengli, has been researching bat coronaviruses since 2004 and focused on the "source tracing of SARS", the strain behind another virus outbreak nearly two decades ago.

"We know that the whole genome of SARS-CoV-2 is only 80 percent similar to that of SARS. It's an obvious difference," she said.

"So, in Professor Shi's past research, they didn't pay attention to such viruses which are less similar to the SARS virus."

Conspiracy rumours that the biosafety lab was involved in the outbreak swirled online for months before Trump and US Secretary of State Mike Pompeo brought the theory into the mainstream by claiming that there is evidence the pathogen came from the institute.

The lab has said it received samples of the then-unknown virus on December 30, determined the viral genome sequence on January 2 and submitted information on the pathogen to the WHO on January 11.

Wang said in the interview that before it received samples in December, their team had never "encountered, researched or kept the virus."

"In fact, like everyone else, we didn't even know the virus existed," she said. "How could it have leaked from our lab when we never had it?"

The World Health Organization said Washington had offered no evidence to support the "speculative" claims.

In an interview with Scientific American, Shi said the SARS-CoV-2 genome sequence did not match any of the bat coronaviruses her laboratory had previously collected and studied.

Rome, Mar 11: Italy has recorded its deadliest day of the coronavirus crisis despite locking down the entire country, as New York deployed the National Guard to contain a disease that has sown worldwide panic.

The hardest-hit country in Europe said its death toll from the COVID-19 virus had risen Tuesday by a third to 631, with the surging epidemic taking its toll on global sporting, cultural and political events.

While authorities in China, where the outbreak began, have declared it "basically curbed", cases are multiplying around the world, sparking panic buying in shops, and wild swings on financial markets.

China remains the hardest-hit overall with more than 80,000 cases and over 3,000 deaths, out of a global total of 117,339 cases and 4,251 deaths across 107 countries and territories, according to an AFP tally.

The virus is infecting all walks of life, including politics, with US Democratic presidential hopefuls Bernie Sanders and Joe Biden both cancelling campaign rallies and British health minister Nadine Dorries saying she had tested positive.

And amid criticism of the US authorities' response, New York deployed the National Guard for the first time during the crisis to help contain the spread of the disease from an infection-hit suburb.

There have been 173 confirmed cases in New York state, including 108 in Westchester County, home to New Rochelle where the majority of infections have been detected.

"It is a dramatic action, but it is the largest cluster in the country. This is literally a matter of life and death," said state governor Andrew Cuomo.

"People are scared, it's an unusual situation to be in," Miles Goldberg, who runs a New Rochelle bar, told AFP.

"It makes people nervous to be around others, it makes people nervous to get inside into businesses and such," he said.

In an unprecedented move, Italian Prime Minister Giuseppe Conte has told the 60 million residents of his country they should travel only for the most urgent work or health reasons.

And while squares in Milan and Rome were emptied of their usual bustle and traffic, some residents appeared uncertain if they were even allowed to leave their homes for everyday tasks like shopping.

The virus has battered tourism around the world, as people scrap travel plans, and a restaurant owner in Florence in northern Italy said that the impact on business had been catastrophic.

"We hope that we will see the end of it, because from around 140 covers a day, this afternoon, we've gone down to 20-25," Agostino Ferrara told AFP.

Pope Francis also seemed to muddy the waters, holding a mass in which he urged priests to go out and visit the sick -- something Conte has specifically discouraged.

Sporting events continued to fall victim to the virus as authorities urge people to avoid large gatherings.

Arsenal's game at Manchester City was postponed after players from the London club were put into quarantine, making it the first Premier League fixture to be called off because of the virus.

The virus has sparked doubts about the Olympics due to open in Tokyo on July 24 and the traditional flame lighting ceremony in Greece is set to be held without spectators.

In the United States, organisers rescheduled the two-week Coachella music festival for October.

The virus and the response to the crisis has prompted pandemonium on global markets with volatility not seen since the world financial crisis in 2008.

After suffering its worst session in more than 11 years at the beginning of the week, the Dow Jones Index in New York bounced back significantly, rising five percent on Tuesday.

Politicians around the world have scrambled to put together emergency packages to ease the significant financial hardships the virus is expected to cause for households and businesses.

US President Donald Trump, who is relying on a strong economy to boost his re-election hopes, promised to announce "major" economic measures on Tuesday.

The biggest item on his wish list is a cut in payroll taxes. But even allies in Congress and reportedly some aides in the White House are sceptical, questioning the cost.

Italy prepared Tuesday to let families skip mortgage and some tax payments while Japan unveiled a second emergency package to tackle economic woes stemming from the outbreak, including $15 billion in loan programmes to support small businesses.

Analysts warned of further volatility ahead however.

"It's like winding up a rubber band. The more you wind it, when you let go, the more it pops," said LBBW's Karl Haeling.

"A lot of the uncertainty goes to the root of the virus itself."

Washington, Jun 27: Facebook has said that it will flag all "newsworthy" posts from politicians that break its rules, including those from President Donald Trump.

Separately, Facebook's stock dropped more than 8 per cent, erasing roughly USD 50 billion from its market valuation, after the European company behind brands such as Ben & Jerry's and Dove announced it would boycott Facebook ads through the end of the year over the amount of hate speech and divisive rhetoric on its platform.

Later in the day, Coca-Cola also announced it joined the boycott for at least 30 days.

CEO Mark Zuckerberg had previously refused to take action against Trump posts suggesting that mail-in ballots will lead to voter fraud, saying that people deserved to hear unfiltered statements from political leaders.

Twitter, by contrast, slapped a "get the facts" label on them.

Until Friday, Trump's posts with identical wording to those labelled on Twitter remained untouched on Facebook, sparking criticism from Trump's opponents as well as current and former Facebook employees.

Now, Facebook is all but certain to face off with the president the next time he posts something the company deems to be violating its rules.

"The policies we're implementing today are designed to address the reality of the challenges our country is facing and how they're showing up across our community," Zuckerberg wrote on his Facebook page announcing the changes.

Zuckerberg said the social network is taking additional steps to counter election-related misinformation.

In particular, the social network will begin adding new labels to all posts about voting that will direct users to authoritative information from state and local election officials.

Facebook is also banning false claims intended to discourage voting, such as stories about federal agents checking legal status at polling places.

The company also said it is increasing its enforcement capacity to remove false claims about local polling conditions in the 72 hours before the US election.

Ethan Zuckerman, director of the Massachusetts Institute of Technology's Center for Civic Media, said the changes are a "reminder of how powerful Facebook may be in terms of spreading disinformation during the upcoming election".

He said the voting labels will depend on how good Facebook's artificial intelligence is at identifying posts to label.

"If every post that mentions voting links, people will start ignoring those links. If they're targeted to posts that say things like 'Police will be checking warrants and unpaid traffic tickets at polls' a classic voter suppression disinfo tactic and clearly mark posts as disinfo, they might be useful," he said.

But Zuckerman noted that Facebook "has a history of trying hard not to alienate right-leaning users, and given how tightly President Trump has aligned himself with voter-suppressing misinfo, it seems likely that Facebook will err on the side of non-intrusive and ignorable labels, which would minimize impact of the campaign."

Earlier in the day, shares of Facebook and Twitter dropped sharply after consumer-product maker Unilever announced a new ad boycott on Facebook, Twitter and Instagram through at least the end of the year.

The European company said it took the move to protest the amount of hate speech online.

Unilever said the polarised atmosphere in the United States ahead of November's presidential election placed responsibility on brands to act.

In addition to the decline in Facebook shares, Twitter ended the day more than 7 per cent lower.

Unilever, which is based in the Netherlands and Britain, joins a raft of other advertisers pulling back from online platforms.

Facebook in particular has been the target of an escalating movement to withhold advertising dollars to pressure it to do more to prevent racist and violent content from being shared on its platform.

"We have decided that starting now through at least the end of the year, we will not run brand advertising in social media newsfeed platforms Facebook, Instagram and Twitter in the U.S.," Unilever said.

"Continuing to advertise on these platforms at this time would not add value to people and society."

Facebook did not immediately respond to a request for comment. On Thursday, Verizon joined others in the Facebook boycott.

Unilever "has enough influence to persuade other brand advertisers to follow its lead," said eMarketer analyst Nicole Perrin.

She noted that Unilever pulled back spending "for longer, on more platforms (including Twitter) and for more expansive reasons" in particular, by citing problems with "divisiveness" as well as hate speech.

Sarah Personette, vice president of global client solutions at Twitter, said the company's "mission is to serve the public conversation and ensure Twitter is a place where people can make human connections, seek and receive authentic and credible information, and express themselves freely and safely."

She added that Twitter is "respectful of our partners' decisions and will continue to work and communicate closely with them during this time."