HOHHOT, Dec. 6 (Xinhua) -- The border city of Manzhouli in north China's Inner Mongolia Autonomous Region has completed the third round of citywide nucleic acid testing for COVID-19, with all samples testing negative, local authorities said Sunday.

The testing started Thursday, and a total of 200,745 people were tested as of 5 p.m. Saturday, according to the city's COVID-19 epidemic prevention and control headquarters.

Manzhouli initiated its first round of nucleic acid testing for all residents on Nov. 22 and the second round on Nov. 27 after two domestically transmitted COVID-19 cases were reported in the city.

A total of eight people tested positive for the virus during the second round of testing covering 203,378 residents.

As of 7 a.m. Sunday, the city had 24 domestically transmitted cases, two asymptomatic cases and one suspected case. Their 1,239 close contacts have been placed under medical observation.