Coronavirus: Beijing closes schools again, cancels 1,255 flights over COVID-19 fears
The new cases have raised fears of a second wave of infections as China had largely brought its domestic outbreak under control.
City authorities on Tuesday had also announced 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 the capital.
Meanwhile, all schools – which had mostly reopened – were ordered to close again and return to online classes.
"The epidemic situation in the capital is extremely severe," Beijing city spokesman Xu Hejian warned at a press conference Tuesday.
Tens of thousands of people in the city linked to the virus cluster – believed to have started in the capital's sprawling Xinfadi wholesale food market – are being tested for the virus, with almost 30 residential compounds in the city now under lockdown.
Beijing has now reported 137 infections over the last six days, with six new asymptomatic cases and three suspected cases on Wednesday, according to the city's health commission.
An additional two domestic cases, one in neighbouring Hebei province and another in Zhejiang, were reported by national authorities on Wednesday, while there were 11 imported cases.
Beijing cancelled at least 1,255 inbound and outbound flights on Wednesday, representing nearly 70 percent of all services, the state-run People's Daily reported, as fears grow over a new coronavirus outbreak.
City officials have urged residents not to leave the city, and several provinces have quarantined travellers from Beijing after more than 130 new cases were confirmed in the capital in recent days.