Fifty-nine positive COVID-19 cases were discovered in north China's Tianjin Municipality during the city's third round of mass nucleic acid testing, local health authorities told a press conference Sunday afternoon.

The cases were registered between 6 a.m. on Saturday and 6 a.m. on Sunday.

Among the positive cases, 23 came from group quarantine centers, 31 from home isolation and the remaining five were from areas that are already under COVID-19 prevention and control. 

Over 12.4 million people were swabbed in this round of testing. 

As of Saturday, 214 locally transmitted confirmed COVID-19 cases, including 78 children, have been detected in the latest resurgence in Tianjin, health officials said.