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 outbreak.
Wuhan in Hubei, the source of the outbreak, is in lockdown and several cities have imposed travel bans.
Health commission officials said on Monday that the number of deaths in Hubei province had climbed from 56 to 76, with four deaths elsewhere.
The overall number of confirmed cases in China is 2,744. State media say more than 300 are critically ill.
More than half a million medical staff have joined prevention, control and treatment operations in Hubei.
Two new makeshift hospitals with at least two-thousand beds are being built and factories are rushing to produce masks and protective clothing.
On 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.
The virus itself is a new, or “novel” coronavirus – a family that normally affects animals.
One human variant causes the common cold – but another variant, Sars, killed hundreds in a major outbreak in 2003. The coronavirus causes severe acute respiratory infection and there is no specific cure or vaccine.