Beijing reported 31 new COVID-19 cases on Tuesday, the municipal health commission said on Wednesday. They're all locally transmitted cases, it added.

The commission also found three suspected cases and six asymptomatic cases in the same period. 

Tuesday's number has brought the total number of local infections in the Chinese capital to 557 since the start of the year. 

It also brought the cumulative infections since June 11 in a new local cluster involving a wholesale market in Beijing's Fengtai District to 137.

The 137 patients are now hospitalized. 

Speaking at a press briefing on Wednesday morning, a municipal official said Beijing is beefing up measures like screening, testing, disinfection and community management to make sure the virus won't further spread.

Beijing is currently at the second emergency response level of COVID-19, closed-off management has been reinstated in all communities across the city, and schools are closed from Wednesday. 

Meanwhile, Beijing will strengthen logistics distribution in the city to ensure stable supply of goods at the retail level. 

Beijing conducted nucleic acid tests on 356,000 people 

Beijing has conducted nucleic acid tests on 356,000 people since June 14, an official said at a regular press conference on Wednesday afternoon. 

During Wednesday's press conference, Pang Xinghuo, deputy director of the Beijing Center for Disease Control and Prevention, gave a brief on the 31 new COVID-19 cases that have been reported in the city.

The 31 patients are 19 males and 12 females and they were all connected to Xinfadi wholesale market, she said, adding that the new cases were detected in five of Beijing's districts: 19 in Fengtai, five in Daxing, three each in Dongcheng and Haidian, and one in Xicheng.

All 137 of the current cases of COVID-19 in Beijing are related to Xinfadi market, among them, 95 percent of the patients are showing mild to moderate symptoms, she noted.

The spread of COVID-19 in Beijing was discovered at an early stage, however, she warned that the number of infections in the city is still likely to increase for a while. 

More areas upgrade risk level to medium

Beijing upgraded another five areas' coronavirus risk level to medium as of 3 p.m. Wednesday.

There are 32 medium-risk areas and one high-risk area, covering nine districts in the city. 

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