China warns SARS-like virus may spread as death toll hits 9

China warned Wednesday that a SARS-like virus could mutate and spread as the death toll rose to nine and the number of cases reached 440 across the country.

The coronavirus is transmitted via the respiratory tract and there "is the possibility of viral mutation and further spread of the disease", National Health Commission vice minister Li Bin said at a news conference.

The commission announced measures to contain the disease as hundreds of millions of people travel across the country for this week's Lunar New Year holiday, including disinfection and ventilation at airports, train stations and shopping centres.

"When needed, temperature checks will also be implemented in key areas at crowded places," the commission said in a statement.

The virus has been detected in some other Asian countries, and the United States confirmed its first case on Tuesday.

The epicentre of the outbreak is the central Chinese city of Wuhan, where authorities have stepped up fever checks at the airport, train stations and highways, while a major Lunar New Year event that draws hundreds of thousands of people was cancelled.