Hebei Province reported 21 new domestic infections as of 10 a.m. on Tuesday, local officials told a press conference, including 16 from capital city Shijiazhuang.

A total of 12 districts and counties have reported cases in Shijiazhuang, with over 76 percent of the infections coming from the Gaocheng District - the only high risk area of COVID-19 pandemic in China.

Shijiazhuang has so far recorded over 300 local cases since January 2.

Over 70 percent of those infected in the city are farmers, the majority of whom are from middle-aged and elderly groups, Li Qi, a Hebei health official, told the press conference.

To rein in the spread of the virus, three cities - Shijiazhuang, Xingtai, and Langfang - which are hit hard by the recent COVID-19 outbreak will be put under close-off management, with people and vehicles not allowed to go out except for necessary needs.

Various Chinese provinces and cities have started tracing and quarantining for people who have stayed or may have come into close contact with confirmed cases in Hebei Province.