CHINA:  Asymptomatic patients and imported infections have become China's chief concern. Mainland China's new coronavirus cases doubled in 24 hours as the number of infected overseas travellers surged, and new asymptomatic infections more than quadrupled.

Mainland China's new coronavirus cases doubled in 24 hours as the number of infected overseas travellers surged, and new asymptomatic infections more than quadrupled.

New confirmed cases rose to 62 on Tuesday from 32 a day earlier, the National Health Commission said, the highest since March 25. New imported infections accounted for 59 of the cases.

The number of new asymptomatic cases rose to 137 from 30 a day earlier, the health authority said on Wednesday, with incoming travellers accounting for 102 of the latest batch.

Chinese authorities do not count asymptomatic cases as part of its tally of confirmed coronavirus infections until patients show symptoms such as a fever or a cough.

As of Tuesday, 1,095 asymptomatic patients were under medical observation in China, with 358 of them travellers arriving from abroad.

To stem infections from outside its borders, China has slashed the number of international flights and denied entry to virtually all foreigners.

It also started testing all international arrivals for the virus this month. Screening of travellers arriving overland was also recently tightened. As of Tuesday, the total number of confirmed cases in mainland China stood at 81,802, including 3,333 fatalities, the National Health Commission said.