Jilin, the outbreak’s epicenter in the northeast, was partially closed down Saturday, while inhabitants of Yanji, a metropolis with almost 700,000 people bordering North Korea, were confined to their homes on Sunday.

Millions of people in China were locked down on Sunday as virus infections nearly tripled to over 3,400 as concerns mounted about the country’s ‘zero-Covid‘ strategy in the face of the largest outbreak in two years.

Also read: China records nearly 3,400 new COVID cases, highest in two years

As nearly 18 provinces combat concentrations of the omicron and Delta strains, officials have closed schools in Shanghai, locked down central neighborhoods in the southern tech powerhouse of Shenzhen, and shut down entire northeastern cities.

The city of Jilin — center of the outbreak in the northeast — was partially locked down Saturday, while residents of Yanji, an urban area of nearly 700,000 bordering North Korea, were confined to their homes Sunday.

China, where the virus was first found in late 2019, has maintained a tight ‘zero-Covid’ policy, enforcing it through rapid lockdowns, travel restrictions, and mass testing when clusters appear.

However, the most recent outbreak, caused by the highly transmissible omicron strain and an increase in asymptomatic cases, is putting that strategy to the test.

Zhang Yan, a Jilin provincial health commission official, admitted that local authorities’ viral reaction had been inadequate thus far.

Also read: China tightens COVID-19 restrictions as cases rise again

“The emergency response mechanism in some areas is not robust enough,” he said at a press briefing on Sunday.

“There is insufficient understanding of the characteristics of the Omicron variant… and judgment has been inaccurate.”

Jilin residents have completed six rounds of mass testing, and the city has reported almost 2,200 cases of the omicron variety since Saturday.

Changchun, a neighbouring city with a population of nine million people, was closed down on Friday, and at least three more small cities have been closed down since March 1.

The mayor of Jilin and the chairman of the Changchun health commission were fired on Saturday, according to state media, demonstrating the political urgency imposed on local officials to limit virus clusters.

However, the strain is visible, with officials increasingly recommending gentler, more focused steps to contain the virus, while analysts warn that severe measures are harming the economy.

Residents in Shenzhen, a southern city of about 13 million people bordering Hong Kong, have been trapped between worries over a new breakout and irritation over the fast, brutal efforts to squash clusters.

Also read: As COVID soars, Chinese city locks down, Shanghai closes schools

“It’s the worst since 2020,” Zhang, a Shenzhen resident, told AFP. “The closures are too sudden, my friend woke up in the morning to find her building was sealed overnight without warning. Her boss had to mail her laptop to her.”

Futian, a Shenzhen subdistrict that was closed down on Sunday, is home to 300,000 people and a flourishing commercial district. It shares a land border crossing with Hong Kong, where the caseload has increased in recent weeks, alarming officials in Beijing.

Hong Kong currently has one of the highest virus-related death rates in the world, as the omicron form decimates its senior population, among whom vaccine reluctance is rampant.

Thousands of foreigners have fled the city as schools have been closed and severe restrictions have been imposed to limit gatherings and mobility two years into a pandemic that has waned in severity across most of the world.

Rather than adopting widespread quarantines, authorities in China’s largest metropolis, Shanghai, have increasingly resorted to temporarily close particular schools, companies, restaurants, and shopping malls due to close-contact fears.

Long lineups have formed outside metropolitan hospitals as people race to receive a negative Covid test.

As the number of cases increases, the country’s National Health Commission declared on Friday that fast antigen tests would be used.

The kits will now be accessible for purchase online or at pharmacies by clinics and ordinary persons for “self-testing,” according to the health authority.

Although nucleic acid tests will continue to be the primary method of testing, the move shows that China believes official efforts will fail to contain the virus.

Last week, a leading Chinese scientist stated that the country, like other nations where omicron has spread like wildfire, should strive to coexist with Covid.

However, the administration has made it plain that mass lockdowns are still an option.