Beijing’s airports cancelled more than 1,200 flights and schools in the Chinese capital were closed again on Wednesday as authorities rushed to contain a new coronavirus outbreak linked to a wholesale food market.

The city reported 31 new cases on Wednesday while officials urged residents not to leave Beijing, with fears growing about a second wave of infections in China, which had largely brought its outbreak under control.

Tens of thousands of people linked to the new Beijing virus cluster — believed to have started in the sprawling Xinfadi wholesale food market — are being tested, with almost 30 residential compounds in the city now under lockdown.

The outbreak had already forced authorities to announce a travel ban for residents of “medium- or high-risk” areas of the city, while requiring other residents to take nucleic acid tests in order to leave Beijing.

Mass testing under way

Officials have closed 11 markets and disinfected thousands of food and beverage businesses in Beijing after the outbreak was detected.