NANJING -- Seventeen airport workers in Nanjing, capital of East China's Jiangsu province, tested positive for COVID-19 as of Wednesday noon, causing massive flight cancellations and delays.

Nine of the workers have been diagnosed as confirmed cases and five as asymptomatic carriers. The remaining three are awaiting further diagnosis, according to a press conference by the municipal government on Wednesday.

Local health authorities found positive results during routine nucleic acid testing for airport staff.

Over 65 percent of flights at the Nanjing Lukou International Airport were canceled as a result. The airport was earlier scheduled to handle 405 inbound and outbound flights on Tuesday.

The airport has carried out disinfection work inside terminal 2, which mainly handles international operations.

The city's Jiangning district launched a massive nucleic acid testing campaign at 9 am Wednesday after multiple airport workers in the district tested positive for COVID-19.

Nanjing, which has a population of more than 9.3 million, plans to carry out citywide nucleic acid testing after the campaign in Jiangning district concludes, according to the municipal government.