People line up at night to receive nucleic acid tests following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 16, 2020. Picture taken June 16, 2020. cnsphoto via REUTERS

A medical worker in a protective suit holds a loudspeaker as people line up outside a site for nucleic acid tests, following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 17, 2020.

A volunteer from the Blue Sky Rescue team, in a protective suit, disinfects the Nangong comprehensive market following a new outbreak of the coronavirus disease (COVID-19) in Beijing, China, June 18, 2020. Picture taken June 18, 2020.

Police and security personnel attempt to prevent the photographer from taking pictures at the barrier surrounding a residential area, near the Xinfadi market, that has been placed under lockdown after a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 20, 2020. REUTERS/Thomas Peter

A child receives a nucleic acid test from a medical worker in a protective suit, following a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 20, 2020.

A security guard takes body temperature measurement of a man at an entrance to a residential compound following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 17, 2020.

People line up to get a nucleic acid test next to a statue of late Chinese leader Mao Zedong at a park in the Fengtai district, after a spike of cases of the coronavirus disease (COVID-19) in Beijing, China June 17, 2020.

A medical worker in a protective suit conducts a nucleic acid test for a resident, following a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 20, 2020.

People wearing face masks are seen near food stalls at a shopping complex, following a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 18, 2020.

A woman receives a nucleic acid test at a makeshift testing site after a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 20, 2020.

A police officer gestures at a photographer as people line up to get a nucleic acid test at a sport center after a spike of cases of the coronavirus disease (COVID-19), in Beijing, China June 17, 2020.

Medical workers rest near a site for nucleic acid tests, following a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 20, 2020.

Volunteers from Blue Sky Rescue team in protective suits disinfect the Yuegezhuang wholesale market, following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 16, 2020. Picture taken June 16, 2020. China Daily via REUTERS

People line up to enter a site for nucleic acid tests, following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 17, 2020.

A blocked entrance of a high school is seen after schools were shut to curb the new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 17, 2020.

Medical workers in protective suits attend to people lining up outside a site for nucleic acid tests, following new cases of coronavirus disease (COVID-19) infections in Beijing, China June 17, 2020.

Medical workers wearing personal protective equipment (PPE) are seen at the entrance of a makeshift testing center, where people will receive nucleic acid tests after a new outbreak of the coronavirus disease (COVID-19) in Beijing, China, June 18, 2020.

A man receives a nucleic acid test at a makeshift testing site in a residential compound after a new outbreak of the coronavirus disease (COVID-19) in Beijing, China June 21, 2020.