The number of new coronavirus cases in an outbreak in China’s north-east tripled on Sunday and authorities tightened control on access to Shanghai in the east.
Bus services in the city of 24 million people were suspended and a negative Covid-19 test was required from anyone who wanted to enter.
The government reported 1,938 new cases on China’s mainland, more than triple the previous day’s total.
About three-quarters of those – 1,412 cases – were in Jilin province in the north-east, where access to the industrial city of Changchun has been suspended.
Families there were told to stay at home following a spate of infections.
China’s infection numbers are relatively low but authorities are enforcing a “zero tolerance” strategy to find and quarantine every infected person.
In Hong Kong, the territory’s government reported 15,789 new daily cases, down by almost half from Saturday’s total.
The territory’s leader, chief executive Carrie Lam, warned on Saturday that the latest infection surge might not yet be past its peak.
Authorities in Jilin are stepping up anti-disease measures after concluding that 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,” he said at a news conference, according to a transcript released by the government.
In Shanghai, China’s most populous city, the number of cases in the latest surge rose by 15 to 432.
The city government called on the public not to leave unless necessary. It said bus services would be suspended from Sunday.
“Those who come or return to Shanghai must have a negative nucleic acid test report within 48 hours before arrival,” said a city health agency statement.
On the mainland, 831 new cases were reported in Changchun, 571 in the nearby provincial capital city of Jilin, 150 in the eastern port city of Qingdao and 60 in Shenzhen, a business centre adjacent to Hong Kong.
Some residents of Cangzhou, south of Beijing, were told to stay at home after nine cases were reported, according to a government notice. It was not clear how many of its 7.3 million people were affected.