Covid-19 control personnel work at an entrance of the Boyaxiyuan community in Beijing’s Haidian district on Tuesday. A resident of the community was found to have the omicron variant on Saturday, leading to the lockdown of the community. Photo: VCG

Workers prepare to distribute commodities to residents of the Boyaxiyuan community on Tuesday. Over 3,400 people are living there. Photo: VCG

Medical workers conduct Covid-19 tests on residents at the Boyaxiyuan community on Tuesday, when the second round of mass testing was launched. Photo: VCG

Residents queue for Covid-19 tests Tuesday in the Baiwang Moli Yuan community in Haidian district of Beijing. Since Monday, part of the community is under closed-off management after one case was found there. Photo: VCG

Covid-19 control personnel work in the locked-down part of the Baiwang Moli Yuan community on Tuesday. Photo: VCG

Security staff help to pass on deliveries to residents at a blocked gate of the Baiwang Moli Yuan community on Tuesday. Photo: VCG

Covid-19 control personnel prepare nucleic acid testing supplies Sunday in a medical center in Haidian district. Photo: Zheng Xinqia/The Paper

A medical worker waits to extract nucleic acid from collected samples Sunday in a lab in Haidian district. Photo: Zheng Xinqia/The Paper

Medical workers test collected samples to detect infections Sunday in the lab. Photo: Zheng Xinqia/The Paper

A police patrol car is stationed Sunday outside a blocked gate of the Boyaxiyuan community in Haidian district of Beijing. The city has reported four cases as of Tuesday. Photo: Zheng Xinqia/The Paper