BEIJING - Millions of residents of China’s southern manufacturing hub of Guangzhou were told on Wednesday to get tested for Covid-19, as infections topped 2,000 for two consecutive days in the city’s worst outbreak so far.

As local cases across China reached their highest level since April 30, the authorities announced on social media that five districts representing more than half of Guangzhou’s population of almost 19 million would need to undergo mass testing.

The latest round of mass testing in Guangzhou comes as China battles a rebound in infections in several economically vital cities, including the capital Beijing, as well as Zhengzhou in central China and southwestern Chongqing, which have dampened hopes that the world’s second-largest economy could ease restrictions soon.

The authorities are determined to get on top of the outbreaks and make good on President Xi Jinping’s zero-Covid-19 policy, without having to impose mass lockdowns of the sort that shut Shanghai earlier this year.

The districts in Guangzhou subject to mass testing this week include Haizhu, which has seen the bulk of the city’s cases. A district-wide lockdown from last Saturday to Monday has been extended to Friday as cases rise.

“My residential compound in Tianhe (district) has been locked up since yesterday,” said Guangzhou resident Jason Li. “I was suddenly notified by my compound. Residents were instructed not to leave our building.”

Mr Li said he had not been told for how long his compound would be locked up. “Thank god I’ve stocked up on groceries recently.”

Some residents whom Bloomberg News spoke to have tried to order items such as toilet paper, medicine and instant noodles in bulk, but have been impeded by disruptions to courier services from the lockdowns.

Those in the districts where stay-at-home orders were imposed are still able to go out for groceries and essentials.

Ms Lily Li, a Guangzhou resident, said the outbreak in the city had worsened in the past two days, having spread to Tianhe, just north of Haizhu. “Honestly, it’s already a huge surprise that Tianhe hadn’t been affected sooner,” she said.

Guangzhou reported 2,637 new locally transmitted Covid-19 cases for Tuesday, up from 2,377 a day earlier amid the city’s most serious outbreak to date and accounting for nearly a third of the 8,176 new local infections reported in China on the day.

In Beijing, new Covid-19 cases jumped to the highest level in more than five months, with officials alarmed by infections being found outside of quarantine that show the virus is still spreading in the community.

The capital reported 78 new infections on Wednesday, the most since May 22. The city has reported double-digit daily cases for most of the past month, though numbers started to spike in recent days, doubling from 39 on Nov 4. Six cases were found outside of isolation facilities, up from one infection the day before.

China, which automatically quarantines anyone with a confirmed case and their close contacts, monitors community transmission as a key indicator of whether an outbreak is under control.

More than 10 buildings and neighbourhoods in Beijing’s central Chaoyang district, where most of the cases have been found, were locked down.

Residents are not allowed to leave their homes or housing complexes unless they are getting a Covid-19 test, and more than 4,400 Communist Party cadres have been dispatched to help with the needs of those under lockdown, said a district official.

Testing frequency has been increased to once a day, for up to five days this week for several districts including Chaoyang, Haidian and Changping.

With the outbreak concentrated in Chaoyang, some residents there reported being sent to quarantine centres after receiving abnormal test results that could indicate Covid-19 infections.

But some schools, day care centres and kindergartens that closed earlier in the week were able to reopen after infection risks have been eliminated.

While Covid-19 cases in China are small by global standards, the policy response has been relentless and mass testing for large populations has been the norm since 2020.

Mass testing is generally free, but some local governments are resuming charges for tests as their finances come under strain amid a slowing economy. In Chengdu, the sprawling capital of southwestern Sichuan province, free Covid-19 tests will end after Nov 30.

Meanwhile, Apple supplier Foxconn said it would continue to maintain closed-loop operations - a system where staff live on-site and isolated from the wider world - at its iPhone factory in Zhengzhou in central China, even as the economic zone that housed the factory lifted a seven-day lockdown.

Foxconn has declined to disclose the number of infections or comment on the conditions of those infected.

The issues at the factory have hit iPhone production, prompting Apple on Monday to say that it expects lower shipments of premium iPhone 14 models. REUTERS, BLOOMBERG