Local governments should avoid unnecessary mass COVID-19 nucleic acid testing, the National Health Commission said on Thursday.

He Qinghua, an official with the commission's Bureau of Disease Prevention and Bureau, said authorities should devise the frequency and scope of testing campaigns based on local epidemic situations.

"Blindly expanding the range of testing should be avoided," he said.

He said COVID-19 lockdown zones should finish the first round of screening within 24 hours, while controlled zones should complete within 48 hours.

Beijing, the capital, has recently required a negative nucleic acid result taken within 72 hours to enter public venues, rather than the previous requirement of a result from within 48 hours.