China: The tech hub of China, Shenzhen went into a weekend lockdown on Saturday as mass COVID-19 testing kicked off in much of the city of 18 million people.

Residents in six districts that account for the majority of the city’s population will be tested twice over the weekend, helping to “minimise the impact on people’s working life,” the city government said in a statement published on Saturday on its official WeChat account.

Lin Hancheng, a Shenzhen public health official, at press concference on Saturday appealed residents to stay home and avoid unnecessary movements. One person from each household will be allowed out from their compound once over the two days to buy food, medicines and necessities, the six districts said.

Shenzhen’s new measures reflect China’s strict adherence to a “dynamic Covid zero” policy of quashing every flare-up.

Earlier on Thursday, 21.2 million people were barred from movement after a sharp rise was reported.