Han Xinxing, executive deputy head of Daxing district, said it had collected around 1.56 million samples for nucleic acid testing by 2 pm Thursday, basically covering all the residents in Daxing.

Daxing is encouraging companies and related institutions to provide free housing or rent reductions to migrant construction workers who will stay in the district during next month's Spring Festival, and they are also being encouraged to pay bonuses to workers.

Han said the district has prepared 39 hotels with 3,424 rooms for possible use as isolation locations for centralized quarantine.

Meanwhile, 1,900 rooms in hotels in other districts, including Chaoyang, have been prepared in case they are needed.

The cluster of infections in Heilongjiang has spread to more cities and other provinces, including neighboring Jilin.

The cluster in Heilongjiang is mainly in Suihua's Wangkui county, which had 65 of the 68 newly confirmed cases in the province.

Jilin reported 33 newly confirmed cases on Wednesday, taking the confirmed caseload in the province to 162 since asymptomatic carriers returning from Heilongjiang triggered an outbreak.