WUHAN/BEIJING • The Chinese authorities have resorted to increasingly extreme measures in the central city of Wuhan to try to halt the spread of the deadly coronavirus, ordering house-to-house searches, rounding up the sick and housing them in enormous quarantine centres.

The urgent, seemingly improvised, steps come amid a worsening humanitarian crisis in Wuhan, one exacerbated by tactics that have left this city of 11 million with a death rate of 4.1 per cent as of Thursday - staggeringly higher than the rest of the country's rate of 0.17 per cent.

As of yesterday, the virus had killed at least 636 people and infected at least 31,161 in mainland China, and many believe the official statistics are far from complete.

With the sick in Wuhan being herded into makeshift quarantine camps, with minimal medical care, a growing sense of abandonment and fear has taken hold, fuelling the sense that the city and the province of Hubei are being sacrificed for the greater good of China.

During a visit on Thursday to Wuhan, Vice-Premier Sun Chunlan said the city and country face "wartime conditions".

"There must be no deserters, or they will be nailed to the pillar of historical shame forever," said Ms Sun, the top official leading the response to the virus.

Enforcing the new restrictions took on aspects of a military campaign, as Ms Sun ordered medical workers to mobilise into round-the-clock shifts to visit each home in Wuhan, check the temperature of all residents and interview close contacts of any infected patients.

Patients are being directed to makeshift hospitals - including a sports stadium, an exhibition centre and a building complex - that are intended to house thousands of people.

It was not clear how the already-strained facilities could handle an influx on the scale that Ms Sun seemed to suggest or whether the new shelters were equipped or staffed to provide even basic care to patients.

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Photographs taken inside the stadium showed narrow rows of simple beds separated only by desks and chairs typically used in classrooms. Some comments on Chinese social media compared the scenes to those from the Spanish flu pandemic, the deadliest in modern history.

The city has already been basically shut down and isolated because of the contagion that began more than a month ago. The new measures came two weeks after China barred people from leaving Wuhan.

It then expanded the restriction to other cities in Hubei province and now confines more than 50 million people - a containment of nearly unimaginable scope.

President Xi Jinping yesterday assured his American counterpart Donald Trump that China is doing all it can to contain the coronavirus. China was gradually achieving results and was confident it could defeat the epidemic with no long-term consequences for economic development, Mr Xi told Mr Trump in a telephone call, according to Xinhua news agency.

He also urged the United States to act "reasonably" in response to the outbreak.

Mr Trump said on Twitter after the phone conversation that Beijing is showing "great discipline" in tackling the outbreak. "Nothing is easy, but he will be successful, especially as the weather starts to warm and the virus hopefully becomes weaker, and then gone."

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The call to the White House came as China accused the US of scaremongering over the epidemic.

But there were increasing signs that the restrictions on entering and leaving Hubei province were slowing the resupply of medicine, protective masks and other necessities, despite pledges by Beijing and by private companies and charities that relief was en route.

"This is almost a humanitarian disaster because there are not sufficient medical supplies," said Adjunct Professor Willy Wo-Lap Lam, at the Centre for China Studies, Chinese University of Hong Kong. "The Wuhan people seem to be left high and dry by themselves."

A widely shared post on Weibo, a popular social media site, said on Thursday that "conditions were very poor" at the Wuhan exhibition centre that has been converted into a quarantine facility. The writer, who said he had relatives in the shelter, cited power failures and problems with heating. He added that people had to "shiver in their sleep".

"Doctors and nurses were not seen to be taking note of symptoms and distributing medicine," said the post. Oxygen devices were also "seriously lacking".

NYTIMES, XINHUA