Residents line up for nucleic acid tests in Southwest China’s Chongqing on Wednesday. To avoid the sweltering heat, the test was conducted from 6 a.m. to noon, and from 6 p.m. to midnight that day. Photo: Ding Gang/Caixin

Testing stations were set up in 11 districts in central Chongqing. Photo: Ding Gang/Caixin

A resident undergoes swabbing at a testing point at the Bishan subway station. The city reported 43 local cases Wednesday and four more infections in the early morning Thursday. Photo: Ding Gang/Caixin

A medical staff member waits inside a testing booth. Photo: Ding Gang/Caixin

Residents prepare to take a nucleic acid test. Photo: Ding Gang/Caixin

To incentivize residents to get tested, the local authority turned affected residents’ health codes from green to orange Wednesday. A green code ensures freedom of movement. Photo: Ding Gang/Caixin

Test takers line up on Bicheng street. More than 3,800 testing points were set up in the city’s central districts. Photo: Ding Gang/Caixin

About 10 million people live in Chongqing’s nine central districts, according to a China Daily report. And the city has reported more than 100 local symptomatic cases since Aug. 3. Photo: Ding Gang/Caixin