A Covid outbreak first discovered in the Chinese city of Nanjing has spread to five provinces and Beijing, with state media calling it the most extensive contagion after Wuhan.
Almost 200 people have been infected since the virus was first detected at the city's busy airport on 20 July.
All flights from Nanjing airport will be suspended until 11 August, according to local media.
Officials also began city-wide testing amid criticism for their "failure".
All 9.3 million of the city's residents - including those visiting - will be tested, said state-controlled Xinhua news.
Posts on social media show long lines of people queuing, and authorities have reportedly urged people to wear masks, stand one metre apart and avoid talking while they wait.
Officials said the highly contagious Delta variant of the virus was behind the infections, adding that cases had spread further because of how busy the airport is.
The cleaners did not follow strict hygiene measures, Xinhua News reported.
Testing has shown that the virus has now spread to at least 13 cities including Chengdu and the capital Beijing.
It is unclear if those infected were vaccinated, BBC reported.
A number of South East Asian countries relying on Chinese vaccines have recently announced they will use other jabs.
China has so far managed to keep the virus largely under control by closing borders and moving quickly to stamp out local outbreaks.
Source: BBC
BDST: 2049 HRS, JUL 31, 2021
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