Beijing reported five locally transmitted confirmed cases of COVID-19 and two asymptomatic carriers on Wednesday as of 3 pm. All were linked to infection clusters at two schools, health authorities said at a news conference.

All the people were quarantined for observation, said Liu Xiaofeng, deputy director of the Beijing Center for Disease Prevention and Control. They have been sent to a designated hospital for treatment, Liu added.

Beijing University of Chemical Technology, which started reporting cases on Monday, has reported 18 positives in the cluster — 13 reported on Tuesday and five on Wednesday, Liu said.

All the cases were linked to the school's campus in Changping district. The school has three campuses in Beijing, with the other two in Chaoyang and Haidian districts.

Four buildings on the campus in Changping district have been designated as high-risk, Bai Lin, deputy head of Changping district, said at the news conference.

The High School Affiliated with Minzu University of China — which started reporting cases on Tuesday — reported three positives, one on Tuesday and two on Wednesday, according to Xu Zhentao, deputy head of Haidian district, where the school is located.

A total of 991 people from the school who have had close contacts with the cases or bear high risk of being infected, have been sent to quarantine, Xu said.