Campuses are still the epicenters of the ongoing COVID-19 epidemic control and prevention work in Beijing, as the cases - especially those related to students - continue to grow, said a senior official at a news conference on Tuesday.

Beijing reported 15 locally transmitted confirmed cases on Monday and 16 more confirmed cases between midnight and 3 pm on Tuesday, according to Liu Xiaofeng, deputy director of the Beijing Center for Disease Prevention and Control.

"All of those cases are from quarantined locations," he said. "Schools should strengthen epidemic control measures by strictly following related regulations in supermarkets, canteens and gyms within campuses."

He also emphasized that people should wear masks properly when they go to hospitals. Several cases reported on Tuesday had been to Civil Aviation General Hospital on Friday where an earlier confirmed case went during the same period.

The patient, who went to the hospital at 4:50 pm on Friday, was confirmed with COVID-19 at 2 am Saturday. The hospital responded immediately by asking 1,264 people to remain in the hospital and 827 others to self-quarantine at home.

All the people in the hospital had completed nucleic acid tests by Tuesday and the results were all negative, according to Wan Gang, deputy head of the hospital.

"No medical staff have been confirmed with COVID-19 so far," he added.

Among the 16 new cases reported between midnight and 3 pm on Tuesday, 12 are students from Communication University of China, which had already reported 28 cases by Monday afternoon.

At present, more than 1,000 people including healthcare workers, police officers and volunteers are working on the university campus to help with epidemic control and prevention measures, Wan said.

"Online teaching for 471 courses started on Tuesday," Li added.

The city of Sanhe in Hebei province, neighboring Beijing, where many residents commute to the capital for work, announced early Tuesday morning that it will start citywide static management for four days from 6 am Tuesday due to its current epidemic situation.

According to the announcement, a person tested positive and several others who had been to places with infection risks in Beijing had also been to Sanhe, which could risk spreading the virus. The city will also conduct four rounds of mass nucleic acid testing for all of its residents starting on Tuesday.