China is the last major economy still committed to a zero-Covid strategy, stamping out new cases with a combination of targeted lockdowns, mass testing and lengthy quarantines.

But virus clusters in recent months have put that approach under strain.

The megacity of Shanghai was forced into a gruelling months-long lockdown and in the capital Beijing, schools were shuttered and residents were ordered to work from home.

Authorities in Beijing eased many curbs earlier this week, but dozens of infections linked to a bar have led them to tighten some restrictions again.

Most primary and middle school students will “continue to study online at home” from Monday, city government spokesman Xu Hejian said at a press briefing today.

The announcement partly walked back a previous decision to send younger pupils back to school in phases, starting next week.

Some 115 cases have been linked to the bar cluster so far, municipal health official Liu Xiaofeng said at the briefing.

The new outbreak was “at a rapidly developing stage … and at a relatively high risk of spreading”, Liu said.

More than 20 million people in Shanghai began a mass testing drive on Saturday that local governments said would take place under temporary lockdown conditions.

The move comes less than two weeks after the eastern economic hub lurched out of a harsh lockdown that was punctuated by food shortages and isolated protests from irate residents.

Officials have maintained a shifting patchwork of restrictions in Shanghai, wary of a virus resurgence after finally containing the country’s worst outbreak in two years.

China recorded 138 domestic infections today, including 61 in Beijing and 16 in Shanghai, according to the National Health Commission.