China has taken only five days to build a 1500-room hospital for COVID-19 patients to fight a surge in infections.
The government says the new outbreak is harder to contain and blames it on infected people or goods from abroad.
The new hospital is one of six with a total of 6500 rooms being built in Nangong, south of Beijing in Hebei province, the official Xinhua News Agency said on Saturday.
China had largely contained the coronavirus that was first detected in the city of Wuhan in late 2019 but has suffered a surge of cases since December.
A total of 645 people are being treated in Nangong and the Hebei provincial capital, Shijiazhuang, Xinhua said. A 3000-room hospital is under construction in Shijiazhuang, due to be finished within a week.
Virus clusters also have been found in Beijing and the provinces of Heilongjiang and Liaoning in the northeast and Sichuan in the southwest.
The latest infections spread unusually fast, the National Health Commission said.
"It is harder to handle," a Commission statement said. "Community transmission already has happened when the epidemic is found, so it is difficult to prevent."
The Commission blamed the latest cases on people or goods arriving from abroad. It blamed "abnormal management" and "inadequate protection of workers" involved in imports but gave no details.
"They are all imported from abroad. It was caused by entry personnel or contaminated cold chain imported goods," said the statement.
A similar program of rapid hospital construction was launched by the ruling Communist Party at the start of the outbreak last year in Wuhan.
The Chinese government has suggested the disease might have originated abroad and publicised what it says is the discovery of the virus on imported food, mostly frozen fish, although foreign scientists are skeptical.
Nationwide, the Health Commission reported 130 new confirmed cases in the 24 hours through to midnight Friday. It said 90 of those were in Hebei.
Meanwhile, researchers sent by the World Health Organisation were in Wuhan preparing to investigate the origins of the virus, which comes after Australia called for an inquiry.
The team, which arrived Thursday, was under a two-week quarantine but was due to talk with Chinese experts by video link.
The team's arrival was held up for months by diplomatic wrangling that prompted a rare public complaint by the head of the WHO.
That delay, and the secretive ruling party's orders to scientists not to talk publicly about the disease, have raised questions about whether Beijing might try to block discoveries that would hurt its self-proclaimed status as a leader in the anti-virus battle.
Australian Associated Press
