The turning point in the COVID-19 cluster inflections in Hebei province is expected in the next few days, a leading expert said.

The province saw three new local cases on Wednesday, the third day in single digits after more than 20 days of double-digit rises. No asymptomatic cases were detected on Wednesday.

"The daily rise in confirmed cases has fallen from nearly 100 at its highest to a single-digit number, which means prevention and control measures have yielded effective results," Zhang Boli, a member of the Chinese Academy of Engineering and an expert in traditional Chinese medicine, said in an interview with China Central Television on Wednesday. He said sporadic cases might still emerge because the virus can survive more easily in cold winter conditions.

With the epidemic under control, normal social activities are gradually resuming in Shijiazhuang, the provincial capital and the hardest-hit place in Hebei. Stay-at-home orders will be lifted in many counties and districts deemed low-risk areas on Friday, officials said at a news conference on Thursday.

As of Wednesday, 377 patients had been discharged from hospitals, including 66 aged over 60, with the eldest 89. From Jan 2 to 10 am on Thursday, the province had reported 934 confirmed COVID-19 cases.

The Chinese mainland witnessed a second daily decrease in recorded cases on Wednesday.

Data from the National Health Commission showed that 41 confirmed cases were recorded, 28 of them in Heilongjiang province, which also recorded eight asymptomatic carriers on Wednesday.

All the cases in Heilongjiang were found in Wangkui county, Suihua, and Harbin, the provincial capital, the provincial health commission said on Thursday.

In Wangkui, the local government is making preparations for villagers in central quarantine to return to their homes, officials said on Thursday.

"A total of 1,127 villagers from the two worst-hit villages in Huiqi township, Wangkui, are now under central quarantine in downtown Suihua," Ma Tianmin, head of the county, said.

Disinfection will be conducted in the villages. Workers will check and maintain facilities including power, water and heating.

As of Wednesday, Heilongjiang had reported 533 confirmed cases and 543 asymptomatic carriers since Jan 10.

Neighboring Jilin province recorded nine confirmed cases on Wednesday, driving the provincial caseload to 303, its health commission said. Eleven asymptomatic carriers were also recorded on Wednesday, taking the total to 92.

Epidemiological investigation has identified patient zero in the cluster in Tonghua, Jilin, a 45-year-old salesman surnamed Lin.

The procuratorate of Dongchang district in Tonghua has guided investigation of the case as Lin is suspected of disturbing the prevention of infectious diseases, CCTV News reported on Thursday.

Lin held workshops for products sold at a health club in Dongchang and tested positive for novel coronavirus during testing of close contacts of confirmed cases and was diagnosed as an asymptomatic carrier of COVID-19 on Jan 12.

Lin's marketing activities caused a "superspreading" event in the city as more cases were reported, most of them in some way connected to Lin, the procuratorate said.

Han Junhong in Changchun contributed to this story.