The capital of northern China’s Hebei province has barred people from leaving the city after it became the hotbed of the recent COVID-19 outbreak.

With Hebei reporting a total 310 COVID positive cases including 183 asymptomatic cases in the past week, capital Shijiazhuang accounted for most of it.

Around 11 million residents of the area are not allowed to leave the city, schools have been suspended, gatherings banned, and residential communities and villages put under closed management.

Both cities have launched citywide nucleic acid testing. The worst-hit Gaocheng District in Shijiazhuang has been classified as a high-risk area for COVID-19, and another 17 areas in Shijiazhuang and Xingtai have been classified as medium-risk areas.

The Chinese mainland on Thursday reported 110 newly positive COVID-19 cases, including 57 asymptomatic cases, the National Health Commission said Friday.

Out of 37 locally transmitted cases, 33 locally transmitted cases were reported in Hebei, two in Liaoning, and one each in Beijing and Heilongjiang, the commission said in its daily report.

The total number of confirmed COVID-19 cases on the mainland reached 87,331 by Thursday, including 521 patients still receiving treatment, 13 of whom were in severe conditions.

Chinese experts are afraid that sheer movement of people during the upcoming Lunar New Year period could fuel the spurt in the new cases, especially now that China is in the middle of one of its worst outbreaks since the coronavirus initially emerged roughly one year ago.