Health officials fear the spread of the virus in the run-up to the country's massive Lunar New Year celebrations. So far, two people have died and there have been 45 confirmed cases in three countries.
Four new cases of an unfamiliar lung illness were reported in China on Saturday, increasing fears that the disease could spread as the country gears up for the most massive human migration on earth. During Chunyun, the period around Chinese New Year, about three billion people move around the country to return home to relatives for the celebration.
This brings the number of confirmed cases up to 45. The new strain of coronavirus has killed two people in the city of Wuhan, where it is believed to have originated in the city's animal market. The World Health Organization has said there is "no clear evidence" that the virus can be transmitted from human to human.
Although the disease is concentrated in Wuhan, two cases have turned up in Thailand and one in Japan, brought by recent visitors to Wuhan. Some of China's neighbors have instituted medical checks at airports.
While coronaviruses often simply cause harmless illnesses such as colds, strains like SARS can cause acute respiratory disease. Scientists have said that this new strain, which has pneumonia-like symptoms, is similar to SARS.
The UK'S Medical Research Council (MRC) has said that there could be as many as 1,700 cases in Wuhan city, and expressed concern about the 19 million people served by Wuhan airport that could facilitate the spread of the virus.
Wuhan's open seafood market has been closed since the outbreak, the MRC said.
China has been on high alert regarding contagious respiratory diseases since the 2002 SARS outbreak killed 800 people and spread to dozens of other countries.
es/mm (AP, dpa)