Seventeen people have tested positive for COVID-19 in Nanjing City, east China's Jiangsu Province, Deputy Mayor Hu Wanjin told a press briefing on Wednesday afternoon. 

Nine cases have been classified as confirmed, up from the seven reported in the morning. 

Another five are asymptomatic, and the remaining three are awaiting confirmation tests.

The 17 people are all cleaning staff at Nanjing Lukou International Airport.

Hu said authorities had traced 157 close contacts of the confirmed cases.

The Nanjing government said it aims to roll out citywide virus testing after finishing testing in Jiangning District, where the airport is located.