NANJING, July 22 (Xinhua) -- Nanjing, capital of east China's Jiangsu Province, launched an all-inclusive nucleic acid testing campaign Wednesday after 17 airport workers tested positive for COVID-19.

Medical personnel continued the testing campaign overnight in residential communities. Community workers and volunteers have been mobilized to help maintain order as people queue for tests.

The mega-city with a population of more than 9.3 million has classified 10 areas as medium-risk for COVID-19 and implemented closed management.

The 17 airport workers were tested positive for COVID-19 during a routine nucleic acid testing for airport staff.

The municipal government has urged residents not to leave the city unless necessary. Anyone leaving the city must produce a negative nucleic acid test certificate issued within 48 hours of their departure. The rule does not apply to transit passengers. Enditem