A Chinese doctor who was reprimanded for warning against a "SARS-like" coronavirus before it was officially recognised died of the virus on Friday, triggering a wave of mourning in China and rare online expressions of anger towards the government.
The death of Li Wenliang, 34, came as Chinese President Xi Jinping assured the United States that China was doing all it could to contain the virus that has killed almost 640 people.
The death toll in mainland China reached 636, with 73 more recorded by Thursday and 3,143 new confirmed infections, taking the total to 31,161 cases, the National Health Commission said.
The new infections were down from Wednesday's figure of 3,694 and 3,887 on Tuesday, but experts warned it was too early to identify a trend.
US President Donald Trump, after speaking to Xi by phone, said China was showing "great discipline" in tackling the virus.
"Nothing is easy, but he will be successful, especially as the weather starts to warm & the virus hopefully becomes weaker, and then gone," Trump said on Twitter. "...We are working closely with China to help!"
Ophthalmologist Li was among eight people reprimanded by police in the city of Wuhan, the epicentre of the flu-like contagion in central Hubei province, for spreading "illegal and false" information.
Li's social media warnings of a new "SARS-like" coronavirus - a reference to Severe Acute Respiratory Syndrome (SARS), which killed almost 800 people around the world in 2002-2003 after originating in China - triggered the wrath of police.
China was accused of trying to cover up SARS.
Li was forced to sign a letter on Jan 3, saying he had "severely disrupted social order" and was threatened with charges.
A selfie of him lying on a hospital bed earlier this week wearing an oxygen respirator and holding up his Chinese identification card was being shared widely online.
"We deeply mourn the death of Wuhan doctor Li Wenliang ... After all-effort rescue, Li passed away," the ruling Communist Party's People's Daily said on Twitter.
Social media users called Li a hero, accusing authorities of incompetence.
"Wuhan indeed owes Li Wenliang an apology," Hu Xijin, editor of the government-backed Global Times tabloid, said on social media. "Wuhan and Hubei officials also owe a solemn apology to the people of Hubei and this country."
Li's death was a "tragic reminder" of how China's preoccupation with maintaining stability drives it to suppress vital information, Nicholas Bequelin, Southeast Asia regional director for Amnesty International said in a statement.
“China must learn the lesson from Li’s case and adopt a rights-respecting approach to combating the epidemic," he said.
Some media described Li as a hero "willing to speak the truth" but there were signs that discussion of his death was being censored.
The topics "the Wuhan government owes doctor Li Wenliang an apology" and "we want free speech" briefly trended on Weibo late on Thursday, but yielded no search results on Friday.
The virus has spread around the world, with 320 cases in 27 countries and regions outside mainland China, a Reuters tally of official statements shows.
Two deaths have been reported outside mainland China, in Hong Kong and the Philippines, but how deadly and contagious the virus is remains unclear, prompting countries to quarantine hundreds of people and cut travel links with China.
There were 41 new cases among about 3,700 people quarantined in a cruise ship moored off Japan, taking the total on board to 61.
Chinese-ruled Hong Kong quarantined for a third day a cruise ship with 3,600 passengers and crew after three people who had been aboard proved infected.
Singapore reported three more coronavirus cases that have not been linked to previous infections or travel to China, prompting it to raise its alert to orange, the same level it reached during the SARS outbreak in 2003.
China has sealed off cities, cancelled flights and closed factories, cutting supply lines to global businesses, so that Beijing resembles a ghost town, with main thoroughfares and tourist spots almost deserted.
The state planner said it was coordinating efforts to boost supplies of staples to Hubei, which has been in virtual lockdown for two weeks.
The majority of US firms with operations in China expect the outbreak to cut revenue this year, and some are accelerating plans to shift their supply chains out of the country, according to a poll by Shanghai's American Chamber of Commerce.
The ramifications are being widely felt.
China's central bank vowed further support for the world's second-biggest economy, with the outbreak expected to knock two percentage points, or more, off its first-quarter growth, from six per cent, analysts said.
Chinese stocks had their worst week since May, while elsewhere in Asia, financial markets slipped after several days of gains.
Foreign investors are also counting the cost.
Toyota Motor Corp and Honda Motor Co extended production suspensions at Chinese plants, as automakers grapple with supply-chain disruptions.