Notices posted in several districts say residents have been ordered to stay at home and barred from receiving non-essential deliveries under a “period of silence” that will last at least until Wednesday. The heightened measures could be extended depending on the results of mass testing, according to the notices.

“Thank you for your understanding and cooperation. Together we can lift the lockdown at the earliest,” said a notice posted in the city’s Huangpu district and posted online.

It’s unclear what caused the new tightening, as the number of new COVID-19 cases in the city continues to drop.

Shanghai reported 3,947 cases in the past 24 hours on Monday, almost all of them asymptomatic, as well as 11 deaths. Authorities have gradually lifted isolation rules for the city’s 25 million residents, but the new orders appear to be reverting to conditions at the start of the outbreak.

Shanghai originally ordered mass testing with limited lockdown, but extended this as the number of cases increased. Thousands of residents have been forced into centralized quarantine centers for showing a positive test result or simply for coming into contact with an infected person.

Two Shanghai residents contacted via social media said they had not been informed beforehand of the new restrictions, which they said could last for up to a week.

“We are not prepared,” said Zhang Chen, a researcher at a technology company. “I packed up thinking it would be my next turn” to be taken to a quarantine facility.

“I don’t know what will happen in May, but after the lockdown, I think I will need psychological help,” Zhang said.

A marketing professional from Pudong West District said the quality of life had declined even as living expenses continued to rise under the lockdown.

“Every time they say the lockdown will be eased after a few days, but there seems to be no end,” said the woman, who asked to be identified only by her last name, Lu, to avoid repercussions from the authorities who have cracked down heavily on dissent.

“All aspects of the job are affected. I don’t know when it will be time for the lockdown to end,” Lu said.

In Beijing, authorities shut down the city’s largest district, with residents told to stay home and shops closed. Beijing ordered daily testing of all residentsclosed parks and other places of leisure and restaurants limited to take-out only.

The usually bustling neighborhood of Sanlitun, filled with restaurants, shops and an Apple store, was virtually deserted. Despite this, retiree Yang Xiaochang said Beijing appeared to be much better prepared to deal with the outbreak than its southern cousin.

“Even if at first there was panic buying…Beijing won’t be like that,” Yang said, referring to Shanghai.

Yet businesses and investors fear that the ruling Communist Party’s “zero-COVID” strategy, which has shut down most businesses in Shanghai and other industrial hubs, could disrupt global trade and activity in the world. automotive, electronics and other industries.

Chinese export growth fell in April as global demand weakened, adding to pressure on the world’s second-largest economy.

Exports rose 3.7% from a year earlier to $273.6 billion, down sharply from March’s 15.7% growth, Customs data showed on Monday. Reflecting weak Chinese demand, imports rose 0.7% to $222.5 billion, in line with growth of less than 1% the previous month.