The number of people killed in China by the coronavirus has risen to 80, with almost 3,000 confirmed ill.
The national new year holiday has been extended by three days to Sunday, in an attempt to contain the spread.
On Monday, Chinese Premier Li Keqiang visited Wuhan, the capital of Hubei province and centre of the outbreak.
The number of deaths in Hubei province has climbed from 56 to 76, with four deaths elsewhere. Wuhan is in lockdown and several other cities have imposed travel bans. The overall number of confirmed cases in China is 2,744. State media say more than 300 are critically ill.
At least 42 cases have been confirmed abroad, including in Thailand, the United States, and Australia. There have been no deaths outside China.
The coronavirus causes severe acute respiratory infection and there is no specific cure or vaccine. Most deaths involve elderly people or those with pre-existing respiratory problems.
New year celebrations were scaled back and four major cities – Beijing, Shanghai, Xian and Tianjin – have banned long-distance busses.
Extending the new year holiday until Sunday means schools and official institutions will remain closed for the rest of this week.
Beijing has closed the Forbidden City for tourists, as well as a section of the Great Wall. In Guangdong province, several cities have made face masks mandatory in public. Both Disney parks in Hong Kong and Shanghai have closed.
Hong Kong, which has eight confirmed cases, has declared a city-wide emergency, with schools closed until 17 February.
Over the weekend, Chinese officials warned the virus was able to spread during its incubation period, making it harder to contain the illness. In humans, the incubation period – during which a person has the disease, but no symptoms – ranges from between one and 14 days, officials believe.