Beijing reported 50 new locally transmitted COVID-19 cases in 24 hours starting Sunday afternoon, bringing the total number of infections to 777 since April 22. Fifteen districts are involved, according to Pang Xinghuo, deputy director of the Beijing Center for Disease Prevention and Control, at a news conference on Monday.

Of the new infections, 41 were reported in controlled zones, and nine were found during community testing, Pang said. Chaoyang district registered 304 cases, the most in the outbreak, followed by Fangshan, which reported 213 cases since April 22. Tongzhou reported 67 cases and Fengtai reported 60 cases during the same period.

"The transmission chain at the community level have not yet been cut completely," Pang said. "New clusters from the communities are the biggest risk for control and prevention work."

She said companies should reduce in-person conferences and adopt online meetings to reduce infection risks. No one should leave Beijing unless it's absolutely necessary.

Because of the increasing number of COVID-19 cases, more residential areas have been designated as high and medium risk. As of Monday afternoon, Beijing had 21 high-risk areas for COVID-19 and 35 medium-risk areas.