According to The Guardian and The Associated Press, China recorded 3,400 new COVID-19 cases on Sunday, up from just under 2,000 on Saturday, marking the worst outbreak since the virus first became common in early 2020.
The majority of the new cases were reported in Jilin Province in northeastern China.
Authorities responded by closing schools and stopping bus service in Shanghai, locking down hundreds of areas in Jilin City, and imposing full lockdowns on several other northeastern cities, the Guardian and AP reported.
As China's rigorous zero-COVID-19 policy continues, millions of individuals have been restricted to their homes.
After public health authorities documented 52 new instances in the city in one day in December and January, the 13 million residents of Xi'an were prohibited from leaving their houses except in emergency situations. The curfew was in effect for a month.
China's state media said that the mayor of Jilin City and a top public health official in neighboring Changchun were both fired on Saturday.
China's authorities shut down its southern economic center of Shenzhen, a city of 17.5 million people, and restricted access to Shanghai by suspending bus service on Sunday in response to a spike in coronavirus cases.
After 60 additional cases were revealed Sunday, everyone in Shenzhen, a finance and technology hub bordering Hong Kong, will undergo three rounds of testing.
All businesses were ordered to close or work from home, with the exception of those that supply food, gasoline, and other needs.
In comparison to other countries like Hong Kong, which reported more than 32,000 cases on Sunday, China's newest infection outbreak has a modest case count.
Authorities on the mainland, on the other hand, are imposing a "zero tolerance" policy and have shut down entire cities in order to discover and isolate every sick person.
Shenzhen is home to some of China's most well-known enterprises, including Huawei Technologies Ltd., BYD Auto, Ping An Insurance Co., and Tencent Holding, which operates the popular WeChat messaging service.
Since the pandemic began in late 2019, China, where the first coronavirus infections were discovered in the central city of Wuhan, has recorded a total of 4,636 deaths on the mainland out of 115,466 confirmed cases.
The number of cases in the latest rise increased by 15 to 432 in Shanghai, China's most populated city with 24 million residents.
The city authority urged residents not to leave unless absolutely essential. Intercity bus service would be discontinued beginning Sunday, according to the statement.
