China's government has responded to a spike in coronavirus infections by shutting down its southern business centre of Shenzhen — a city of 17.5 million people — and restricted access to Shanghai by suspending bus services.
Everyone in Shenzhen will undergo three rounds of testing following 75 new cases being recorded on Sunday.
All businesses except those that supply food, fuel and other necessities were ordered to close or work from home from Monday.
China reported almost 3,400 new cases on Sunday — 1,938 symptomatic cases (more than triple the previous day's total) and 1,455 asymptomatic cases — according to China's National Health Commission.
The commission reported 2,343 cases on Monday (including 906 asymptomatic cases) across the country on Monday.
Those new daily cases are the highest numbers mainland China has seen since the pandemic began more than two years ago.
The surge prompted health authorities to allow the public to buy rapid self-test kits for the first time to help detect infections quickly, as some experts said China's earlier strategy — based on nucleic acid tests, which required medical workers to take samples — had become harder with the fast-spreading Omicron variant.
Case numbers in China's latest infection surge are low compared with other countries and with Hong Kong, which reported more than 32,000 cases on Sunday.
But mainland authorities are enforcing a "zero-tolerance" strategy and have locked down entire cities to find and isolate every infected person.
Shenzhen is home to some of China's most prominent companies, including telecom equipment maker Huawei, electric car brand BYD Auto, Ping An Insurance and Tencent Holding, operator of the popular WeChat message service.
About three-quarters of the cases were in Jilin province in the north-east, where the industrial metropolis of Changchun was placed under lockdown on Friday and families were told to stay home after a spate of infections.
China, where the first coronavirus cases were detected in late 2019 in the central city of Wuhan, has reported a total of 4,636 deaths on the mainland out of 116,902 confirmed cases since the pandemic started, according to the National Health Commission.
In Shanghai, China's most populous city with 24 million people, the number of cases in the latest surge rose by 41.
The city government called on the public not to leave unless necessary.
It said the intercity bus service would be suspended starting on Sunday.
"Those who come or return to Shanghai must have a negative nucleic acid test report within 48 hours before arrival," a city health agency statement said.
Hong Kong drives down infections
In Hong Kong, a health official warned the public not to assume the territory's deadly coronavirus surge was under control as the government reported 190 new fatalities, most of them elderly people, and 32,430 new cases.
That Is down from above 50,000 after stringent travel and business curbs were imposed.
Hong Kong, a crowded financial hub of 7.4 million, is trying to contain an outbreak that has killed 3,993 people, most of them in the latest surge driven by the Omicron variant, and swamped hospitals.
"People should not get the wrong impression that the virus situation is now under control," Albert Au, an expert with the government's Centre for Health Protection, said.
Construction crews sent from the mainland have built temporary isolation centres in Hong Kong for thousands of patients.
Back on the mainland, authorities in Jilin are stepping up anti-disease measures after concluding their earlier response was inadequate, according to Zhang Yan, deputy director of the provincial health commission.
"The emergency response mechanism in some areas is not sound enough," Mr Zhang said at a news conference, according to a transcript released by the government.
Also on Sunday, some residents of Cangzhou, south of Beijing, were told to stay home after nine cases were reported there, according to a government notice.
It was not clear how many of the 7.3 million people there were affected.
AP/ABC
