Authorities in Dalian City in northeast China's Liaoning Province launched a citywide nucleic acid testing campaign after two new locally COVID-19 cases were reported on Monday.

The testing began on Tuesday and will continue for three days, with the aim of testing all residents in the city, said authorities.

Passengers with plans to fly out of the city need to provide a negative nucleic acid test result within seven days, the city's airport said in a statement.