Medical workers collect a throat swab from a citizen at a nucleic acid testing site in Haidian District of Beijing, capital of China, June 18, 2020.File photo:Xinhua

Shijiazhuang, capital city of North China's Hebei Province, has entered " wartime mode" as sporadic cases resurged in the province. 

The city will carry out a comprehensive epidemiological investigation into the relevant personnel and strengthen prevention and control measures in key areas, according to Shijiazhuang government officials.

Authorities in Hebei, the province neighboring Beijing, reported four new confirmed local cases and 13 new silent virus carriers on Monday. 

China has seen sporadic cases in several cities recently.

In addition to Shijiazhuang, two cities in Northeast China's Liaoning Province, Dalian and Shenyang, also entered "wartime" mode on December 20 and December 30, 2020, respectively in a bid to prevent the spread of the disease. 

The Chinese mainland reported 33 new confirmed cases on Monday, including 13 local transmissions.