More than 10,000 market workers and close contacts will be tested, as will anyone in Beijing or neighboring Tianjin city and Hebei province who has visited Xinfadi or had close contact with Xinfadi visitors since May 30.
State-controlled Beijing News said six wholesale food markets in the city recently visited by the two men had been either wholly or partially shut.
On Saturday, the city had announced six new cases from the previous day after an outbreak was detected in the large wholesale market of Xinfadi, which has been sealed along with five others in the capital.
Beijing has tightened COVID-19 control measures after the newly confirmed cases by local transmission. A plan to allow Beijing's first- through third-graders to resume classes Monday was canceled.
45 people out of 517 tested with throat swabs at the Xinfadi market in the city's southwestern Fengtai district had tested positive for the coronavirus, district official Chu Junwei said at a briefing. These include restrictions on people arriving into Beijing from elsewhere in China, while only Chinese citizens are allowed to enter the country from overseas, although a few exceptions have been granted to businesspeople resident in China wanting to return.
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In response to the emergency, Fengtai district has been put on "wartime" activity with close management of the 11 residential areas around Xinfadi market.
They are said to be unsure of how far the virus has spread from the Xinfadi wholesale market, which is said to supply 80 percent of Beijing's vegetables and meat. Beijing authorities had earlier halted beef and mutton trading at the market and had closed other wholesale markets around the city. New cases have been linked to nightlife establishments, church services, a large-scale e-commerce warehouse and door-to-door sellers. That was the highest since mid-April and included 36 in the capital, Beijing, a city of 20 million people. Some coronavirus hotspots, including NY, have reported significant declines in infections, but the United States continues to have by far the world's highest number of deaths and cases.
Police cars patrolled the streets outside the blocked-off neighbourhoods, and AFP reported a bus carrying workers in hazmat suits. Fengtai district officials said a "wartime mechanism" and "field command center" has been established to deal with this fresh wave.
Almost everyone who tested positive had worked or shopped at the market, which employs upwards of 10,000 people.
Attention focused on the market after the reports of the first three cases on Thursday and Friday.