Authorities in Beijing said on Monday they had launched a blanket search and testing campaign among the city's construction sites, where three confirmed COVID-19 cases emerged.

The Beijing Municipal Commission of Housing and Urban-Rural Development told a press conference on Monday afternoon that three cases were reported from two construction sites in Beijing.

The commission said it had checked 435 projects in the city, and given nucleic acid tests to 1,622 people there who had visited or contacted people from the Xinfadi food market, to which a number of new infections were related.

The two construction sites, where the confirmed cases were reported, have been put under closed-off management, it said.

Ding Sheng, vice director of the commission, said all construction sites that had workers exposed to the Xinfadi market will suspend personnel entry and exit.

They have been asked to disinfect their offices, dormitories, canteens, and restrooms while tightening checks on their food supplies, Ding said.

The Chinese capital on Sunday reported nine newly confirmed domestically-transmitted COVID-19 cases, down from 22 reported on Friday and Saturday respectively, the municipal health commission said.

From June 11 to 21, Beijing reported a total of 236 confirmed domestically-transmitted cases.