Shijiazhuang City in north China's Hebei added nine medium-risk COVID-19 areas, in addition to one high-risk region, the Gaocheng district, local health commission announced on Friday.

The move came after the city reported 31 new locally-transmitted confirmed cases and 35 asymptomatic cases over the past 24 hours. 

Hebei now has 17 medium-risk areas and one high-risk area. The other eight medium-risk COVID-19 areas are in Xingtai City, where infection resurgences have also been recorded lately.

The source of the cases resurgence in north China's Hebei Province hasn't been identified, said Xu Jianpei, Vice Governor of Hebei, on Friday.

By 10 a.m. BJT on Friday, there were 127 locally-transmitted cases in Hebei and 183 asymptomatic cases.