Workers install barbed wire on fences in the Beijing Institute of Technology campus on Sunday. Beijing’s Haidian district, housing China’s top universities, has tightened controls to contain the transmission of Covid-19. Some universities have confined students to the campus. Photo: Ding Ke (intern)/Caixin

Some parents of students wait outside Renmin University’s west gate to receive their children on Sunday. Photo: Ding Ke (intern)/Caixin

A taxi waits at the west gate of Renmin University of China. Several students from Renmin University of China confirmed with Caixin that the school issued a notice on Saturday evening allowing students to leave for home. Photo: Ding Ke (intern)/Caixin

Students with suitcases gather at the west gate of Renmin University of China on Sunday. Some universities in Haidian district have encouraged students to return to their hometowns as Beijing’s Covid-19 outbreak drags on. Photo: Ding Ke (intern)/Caixin

Students at the west gate of Renmin University of China set off for the airport or railway station. Photo: Ding Ke (intern)/Caixin

The east gate of Renmin University of China is empty Sunday. Photo: Ding Ke (intern)/Caixin

A quiet Sunday at the southeast gate of Peking University in Beijing’s Haidian district. Photo: Ding Ke (intern)/Caixin

Volunteers on duty behind the closed north gate of Beijing Foreign Studies University’s east campus in Haidian district on Sunday. Students of this school are not allowed to leave the school in principle, according to volunteers on site. Photo: Ding Ke (intern)/Caixin

A delivery worker passes a takeout order to volunteers at the east campus gate of Beijing Foreign Studies University on Sunday. Photo: Ding Ke (intern)/Caixin

The southeast gate of Beijing Institute of Technology’s Zhongguancun campus has been sealed with hoarding. The capital reported 41 new local cases on Tuesday, with 12 detected in Haidian district. Photo: Ding Ke (intern)/Caixin