Beijing is still facing a grim and complex epidemic prevention and control situation, as clusters and sporadic cases are appearing simultaneously and the risk of hidden spread still exists, officials said on Wednesday.

"We must adhere to the dynamic zero-COVID strategy and work against time to stop the spread of the virus," Liu Xiaofeng, deputy director of the Beijing Center for Disease Prevention and Control, said at a news conference on Wednesday.

Between midnight and 3 pm on Wednesday, Beijing reported 57 locally transmitted COVID-19 infections, with 33 asymptomatic carriers.

Fifty-three of the confirmed cases were found among those under quarantine and the other four were detected at the community level.

Twenty-seven confirmed cases were reported in Chaoyang district, 11 in Tongzhou district, seven in Changping district, three in Shunyi district, two each in the districts of Xicheng, Haidian and Fengtai, and one each in the districts of Dongcheng, Daxing and Yanqing.

Seventeen more areas in Chaoyang district have been classified as high-risk areas, according to Meng Rui, deputy director of the district.

"More than 9,600 regular staff members are sticking to their posts to ensure prevention and control of the epidemic, residents' daily life and medical services," said Meng. "Via various methods, they have strengthened the publicity and guidance of epidemic prevention and control policies and solved residents' demands in a timely manner."

"To ensure residents' normal work and life, departments are working hard to optimize and improve epidemic prevention policies and control measures for those who return to Beijing," said Xu Hejian, spokesman of the municipal government. "Residents can direct their comments or questions to the 12345 hotline or 'Beijing 12345' WeChat public account."