3 test positive for COVID-19 in North China's border city

HOHHOT -- Three people tested positive for COVID-19 on Saturday in China's border city of Manzhouli, North China's Inner Mongolia autonomous region, according to the city's COVID-19 prevention and control headquarters.

The cases were detected during a routine nucleic acid testing of workers at high risk of infection.

An epidemiological investigation was immediately launched and the residential areas and workplaces visited by the COVID-19 positive cases have been put under closed-loop management.

According to the authorities, a mass testing will soon be launched.