Chinese health authorities urged people in the city of Wuhan to avoid crowds and public gatherings, after warning on Wednesday that a new viral illness that has infected hundreds and caused at least nine deaths could spread further.
The number of new cases has risen sharply in China, the centre of the outbreak. There were 440 confirmed cases as of midnight Tuesday in 13 jurisdictions, said the deputy director of the National Health Commission. Nine people have died, all in Hubei province, since the outbreak emerged in its provincial capital of Wuhan late last month.
More Wuhan residents went out to buy masks on Wednesday, with some saying that they had shelved travel plans for Chinese New Year and would stay at home instead.
The illness comes from a newly identified type of coronavirus, a family of viruses that can cause the common cold as well as more serious illnesses such as the SARS outbreak that spread from China to more than a dozen countries in 2002-2003 and killed about 800 people.
Other countries have stepped up screening measures for travellers from China, especially those arriving from Wuhan. Worries have been heightened by the coming of the Lunar New Year holiday rush when millions of Chinese travel at home and abroad.
Officials said it was too early to compare the new virus with SARS or MERS, or Middle East respiratory syndrome, in terms of how lethal it might be. They attributed the spike in new cases to improvements in detection and monitoring.
Health officials confirmed earlier this week that the disease can be spread between humans after finding two infected people in Guangdong province in southern China who had not been to Wuhan.