The US has said it has asked all its non-essential staff and their family members at the Shanghai consulate to leave, in Washington’s latest response to the financial hub’s handling of the worsening Covid outbreak.

The state department ordered the departure “due to the ongoing Covid-19 outbreak” there, according to a spokesperson from its Beijing embassy. “It is best for our employees and their families to be reduced in number and our operations to be scaled down as we deal with the changing circumstances on the ground,” the person said on Tuesday.

Washington’s latest move came after the state department on Friday announced that non-emergency personnel could voluntarily leave the Shanghai consulate. It is not clear why the departure of those workers had become mandatory in a short span of a few days.

China responded angrily to the earlier voluntary departure order, saying Beijing was “strongly dissatisfied” with and “firmly opposed” the US’s “groundless accusation” about China’s Covid policy.

Shanghai’s handling of the latest Covid outbreak has made international headlines in the last few weeks. But the most controversial of its practices had been separating Covid-positive children from their parents. Although the authorities have since made some concessions, the state department cited the risk of parents and children being separated in its announcement.

Shanghai on Tuesday reported 22,348 new asymptomatic coronavirus cases and 994 symptomatic cases for 11 April, the local government said. Asymptomatic cases were down from 25,173 a day earlier. The symptomatic cases rose from 914.

The harsh lockdown in China’s most populous city – home to nearly 26 million people – has also caused a backlash among its residents. In the last few weeks, many patients have complained about being unable to access medical care facilities. Stories of food shortages have prompted citizens in other parts of China to rush to stockpile goods.

The situation in Shanghai has also led the EU chamber of commerce to warn that China’s zero-Covid strategy was “eroding foreign investors’ confidence”. In a letter, it urged the Chinese government to shift its approach by giving the Chinese population access to mRNA vaccines and allowing people with mild symptoms to quarantine at home.

Despite international pressure, Beijing did not seem able to adjust its zero-Covid policy, said Chen Zhengming, a professor of epidemiology at Oxford University. “China is in such a dilemma right now that if it sticks to this policy there’d be big burden to the economy and cause secondary disasters such as [those] in medical care. But if it loosens the policy, there may be a huge spike in new infections.”

On Monday, Shanghai authorities started easing lockdown in some parts of the city, despite reporting a record of more than 25,000 new Covid cases. Residents of neighbourhoods where there have been no positive cases for at least two weeks were allowed some degree of freedom, but they were not allowed to travel to those still under severe lockdowns.

Chinese officials admitted the situation in Shanghai was concerning. “The epidemic is in a rapid increase phase, with social transmission still not brought under effective control,” said Lei Zhenglong of the National Health Commission at a briefing in Beijing on Tuesday. “The forecast for the next few days is that the number of infected people will remain at a high level.”