TIANJIN, Dec. 1 (Xinhua) -- North China's Tianjin Municipality found no new cases of COVID-19 from its latest round of nucleic acid testing involving six groups of people in the Binhai New Area, local authorities said Tuesday.

The testing, which took place between Nov. 28 and 30, involved 493,745 samples and all tests came back negative, according to the COVID-19 epidemic prevention and control headquarters of the Binhai New Area.

The municipality conducted nucleic acid tests for all residents in the area between Nov. 21 and 23 after several COVID-19 cases emerged there last month.

The latest testing drive included workers handling imported goods and those having contact with overseas arrivals, and residents living in the same residential complexes as them.

Other groups tested included couriers, bus and taxi drivers, medical personnel, and those working in schools, kindergartens and nurseries.