Residents line up to take the Covid-19 test Sunday in North China’s Tianjin. The city reported two new local cases on Saturday, which were confirmed as omicron variant on Sunday. Photo: VCG

A resident organizes food on a car on Sunday in Tianjin. People started to gather at food markets to prepare for possible lockdowns following the detection of cases. Photo: The Paper

Vegetables and fruits at a stall are sold out on Sunday in a market in Hedong district of Tianjin. Photo: Chen Xiao/Caixin special contributor

People buy vegetables and food in a market in Tianjin on Sunday. Photo: Chen Xiao/Caixin special contributor

People wait to get their Covid-19 tests at a testing point in Tianjin on Sunday, the day the city ordered mass testing to nearly 14 million residents to control the transmission of omicron. Photo: The Paper

A kid takes a Covid-19 test Sunday in Tianjin. Twenty cases mean the virus has been spreading in the community for a while, the Tianjin Center for Disease Control and Prevention said at a press conference on Saturday. Photo: The Paper

A medical worker conducts a Covid-19 test for a resident Tuesday in Central China’s Henan province. Two local infections that have been confirmed as the omicron variant in Anyang city of the province are believed to be linked to the same transmission chain as the existing cases in Jinnan district of Tianjin. Photo: Chen Liang/Caixin

Residents wait to take Covid-19 tests Tuesday in Zhengzhou, Henan. Photo: Chen Liang/Caixin

People queue in line in the snow to get tested in Zhengzhou on Tuesday. From Jan. 3 to Jan. 9, Zhengzhou carried out three rounds of mass testing and administered over 35 million tests. Photo: Chen Liang/Caixin

People get tested in Zhengzhou on Tuesday. The city launched a new round of mass testing today for residents who live in nine districts. Photo: Chen Liang/Caixin

Henan reported over 250 local cases between Dec. 31 and Jan. 9. Photo: Chen Liang/Caixin

A check point for the epidemic prevention is set Wednesday on a highway in Luoyang, Central China’s Henan province. Photo: VCG

Fences are set up on a street of a locked-down community Saturday in Zhengzhou. Henan has designated 12 Covid-19 high-risk areas and eight medium-risk areas on Sunday. Photo: VCG