Photo: Screenshot of Weibo video

One campus of a university in Beijing was sealed off after an environmental monitoring sample came back positive for COVID-19 on Wednesday, one day after the capital city lifted the lockdown on all affected communities. 

The University of the Chinese Academy of Sciences organized  mass nucleic acid testing of students and faculty staff in the affected Olympic Village campus located at the Datun Road in Beijing's Chaoyang district. No positive results were found as of Wednesday evening. 

A student surnamed Zhang, told the Global Times on Wednesday that they received a notice from the university in the morning requiring students to take tests for COVID-19 and stay in the dorm for quarantine.

The campus was temporarily sealed off according to Beijing News Radio. 

Officials from the Olympic Village subdistrict said the positive sample was detected during a routine testing in the university. A larger scale environmental monitoring work in the area is still under way. 

The National Zoological Museum of China and several restaurants near the campus were also closed for epidemic concerns.

On Tuesday, Beijing announced it had cleared all sealed off areas after lockdown of two communities hit by the epidemic in Wangjing, Chaoyang district, was lifted.