North China's Tianjin Municipality on Friday confirmed four more domestically infected COVID-19 cases.

The four lived or worked in the Kanhaixuan Community in Dongjiang Port District, local authorities said.

They had tested negative for coronavirus on November 10 in a nucleic acid test after an asymptomatic case was reported in the community. However the four returned positive results on Thursday night in a follow-up test.

The community was listed as a high-risk area starting from 2 a.m. on Friday.