A city in northeastern China has re-imposed lockdown measures after diagnosing 12 new COVID-19 cases in three days, state-run newspaper People’s Daily reported Monday.

Health authorities in Jilin province announced Friday that Shulan, a city of 630,00 people, had identified one confirmed COVID-19 case: a 45-year-old woman. Two days later, the local government reported that 11 more people had tested positive for COVID-19, all of them close contacts of the woman.

Following the announcements, Shulan adjusted its coronavirus risk level from low to medium, then medium to high. Residential communities were put under lockdown in a bid to curb the spread of the virus, with new measures including closing schools and resuming online classes, as well as prohibiting gatherings such as dinners at restaurants.

As of Monday, Shulan is the only “high-risk” city or region in China.

Meanwhile, Jilin, the second-largest city in the province of the same name, announced three confirmed COVID-19 cases on Monday, all of them linked to the cases in Shulan.

Jilin is not the only province to experience a sudden rise in COVID-19 cases recently, even as the novel coronavirus has been largely contained in China.

In April, the city of Suifenhe in neighboring Heilongjiang province imposed a lockdown after detecting dozens of new COVID-19 infections among Chinese nationals returning from Russia. Suifenhe lowered its risk level to low and lifted its monthlong lockdown measures last week, after all returnees from abroad were released from compulsory 14-day quarantine periods, according to Xinhua Net.

Also on Monday, Wuhan, the central Chinese city where COVID-19 was first detected, reported five new cases, all among residents in the same housing community.

Editor: David Paulk.

(Header image: A disease control and prevention worker disinfects an elevator at a residential community in Shulan, Jilin province, May 10, 2020. Zhang Nan/Xinhua)