Shanghai reported two COVID-19 confirmed cases and one asymptomatic case on Friday, after the city reopened on Wednesday and was in the process of restoring work and production.

The three cases were found outside the quarantined population in Huangpu, Xuhui and Baoshan districts, and the neighborhoods where the cases live have been classified as medium-risk zones.

Wu Jinglei, director of the Shanghai Health Comission, said the situation of epidemic prevention was still "complicated and grave", and the government will continue upholding the "dynamic zero-COVID" principle as it improves its testing capacity and early warning system and implements constant preventative measures.

Yu Linwei, vice-governor of Xuhui district, said in the past two days of the city's reopening, testing stations in Xuhui have sampled more than 400,000 people every day.

Yu said long queues in front of testing sites have caused inconvenience for residents, and the district will open 24-hour testing services at subdistrict health centers and deploy mobile testing squads.

Meng Qingyuan, vice-governor of Baoshan district, said the neighborhood which was put under control due to the new infection contained 3,200 people, and 41 percent of them were over 60.

Meng said the district had formed task forces to serve more than a dozen residents aged above 90 and those who need regular medical treatment for cancer and hemodialysis, and those task forces will continue one-on-one services for them.

As the three-day Dragon Boat Festival holiday began on Friday, Huangpu district imposed pre-registration for its popular Yu Garden and deployed 1,530 security personnel to the Bund and Nanjing Road pedestrian malls.

Yu Yuan, vice-governor of Huangpu district, said all parks and public spaces have set up venue codes and temporary quarantine zones in case of emergency.

Meng said the 27 parks open in Baoshan have received 29,000 people on Friday, and capped visitor capacity to 50 percent of the maximum.