The North China municipality of Tianjin will began city-wide nucleic acid testing for its whole population of 13.7 million for two consecutive days beginning Thursday.

The city just conducted the testing on Tuesday. It recorded five local confirmed COVID-19 cases and 240 asymptomatic carriers on Tuesday, with 36 detected at the community level, according to local health commission on Wednesday.

Primary schools, kindergartens, vocational schools and off campus training institutions in 10 out of 16 city districts have been closed and their classes moved online since Wednesday morning.