BEIJING - Mainland China's new coronavirus cases doubled in 24 hours as the number of infected overseas travelers surged, and new asymptomatic infections more than quadrupled, pressuring authorities to tighten measures to stem local transmissions.
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 more than quadrupled to 137, the health authority said on Wednesday, with incoming travelers accounting for 102.
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.
To stem infections from outside its borders, China has slashed the number of international flights and denied entry to virtually all foreigners.
The government has recently tightened screening of travelers arriving overland.
China also maintains strict health screening protocols domestically, concerned about any resurgence in domestic transmissions, especially among virus carriers who exhibit no symptoms.
The rise in new cases came as curbs on the central city of Wuhan, in lockdown since January, were lifted. The capital of Hubei province saw just two new confirmed infections in the past 15 days.
China sealed off the city of 11 million people to stop the spread of the flu-like virus to other parts of the country. Over 50,000 people in Wuhan caught the virus, and more than 2,500 of them died, according to official figures.
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.