COVID-19 cases have been reported from mass nucleic acid tests involving nine districts in Beijing for the past seven consecutive days, a senior official said on Monday.

Beijing reported 63 new locally transmitted COVID-19 cases between 3pm Sunday and 3pm on Monday, bringing the total number of infections to 1,556 since April 22. Sixteen districts are involved, Liu Xiaofeng, deputy director of the Beijing Center for Disease Prevention and Control, said at a news conference on Monday afternoon.

"Of the new infections, 58 were reported in controlled zones, and five were found from mass nucleic acid tests at community level," he said.

Recently Beijing reported several clusters involving a university campus, a wholesale market and a subway renovation project.

"Some new locations such as Youyi residential community in Haidian district and Oriental Plaza in Dongcheng district have risks of infection," Liu said. "The epidemic situation is still severe and complicated."

Of all 1,556 cases, Chaoyang district registered 415, the most in the outbreak, followed by Fangshan, which reported 404. Fengtai has reported 307 and Haidian 192 .

As of Monday, Beijing had 10 high-risk areas for COVID-19 and 25 medium-risk areas.