China reported its highest daily rise in local Covid-19 cases in 21 months as infections more than doubled in the north-western city of Xian, China’s latest Covid hot spot.

The city of 13 million, which entered its fourth day of lockdown, detected 155 domestically transmitted cases with confirmed symptoms for Saturday, up from 75 a day earlier, official data showed on Sunday.

That drove the national daily count to 158, the highest since China managed to contain a nationwide outbreak in early 2020.
Xian, with 485 local symptomatic cases reported for the December 9-25 period, has imposed heavy-handed measures to rein in the outbreak, in line with Beijing’s policy that any flare-up should be contained as soon as possible.

The city managed to quickly detect those cases through three rounds of mass testing, He Wenquan, a Xian official, told reporters on Sunday, adding that high case numbers could persist into the next couple of days.

“In order to quickly screen out the infected groups of people, after an analysis by experts, we will step up control measures in key areas, especially places with greater risk level,” He said.

The local government also announced that it would launch a citywide disinfection campaign from 6pm local time, urging residents to shut the windows and bring clothes or other items inside from their balconies.

Residents may not leave town without approval from employers or local authorities and multiple rounds of mass testing were conducted to identify cases.