A total of 57 new asymptomatic cases of the novel coronavirus, with three of them imported, were reported on Tuesday on the Chinese mainland, Mi Feng, spokesman for the National Health Commission, said at a news conference on Wednesday.

People board a customized train heading for East China's Zhejiang province at Zhoukou East Railway Station in Zhoukou, Central China's Henan province, Feb 22, 2020. (Photo: Xinhua)

On Tuesday, seven such cases were confirmed and 32 asymptomatic cases were discharged from medical observation, bringing the total number of asymptomatic cases still under observation to 1,023 of which 228 were imported from abroad.

As of Tuesday, a total of 6,764 people were reported with asymptomatic infections nationwide, 588 of them imported. Among them, 1,297 were confirmed, of which 251 were imported.