The authorities' decision to lift restrictions on buying fever, cold and anti-inflammatory drugs this month had also led to a surge of online orders as COVID patients exhibiting mild symptoms were allowed to recover at home.

All parcels sitting around for more than three days have been cleared, said Ma Wei, who oversees logistics in Beijing at e-commerce company JD.

"The 'arrival the next day' service will gradually resume this week," he said.

Ma said around 2,000 delivery drivers had been dispatched to Beijing over the past week to replenish its courier workforce after hundreds of their Beijing counterparts fell ill and asked for sick leave. The company normally has around 15,000 delivery staff in Beijing.

Yao Hongxu, deputy general manager of SF Express' Beijing division, said the parcel delivery company was past the worst, when Omicron knocked out half of his 18,000-member fleet.

To bridge the shortfall, the company borrowed 500 couriers from out of town, and arranged another 500 employees from nondelivery posts to fill the vacancies.