Meanwhile, Shanghai on Friday began free testing in areas deemed to have low risk of COVID-19 exposure to identify potential infections, according to the municipal health authorities. The free testing will last till Sunday.

But a closed-loop management system will not be imposed in these areas, Wu Jinglei, director of the Shanghai Municipal Health Commission, said at a briefing on Friday.

"The number of infections on Thursday is relatively higher than those announced in the past few days, because most of the patients were identified through testing carried out in key neighborhoods across the city over the past two days," Wu said.

To curb the spread of the virus in the city, the Shanghai Civil Affairs Bureau on Friday advised residents to stagger their visits to cemeteries and mausoleums during the Tomb Sweeping Day holiday from April 3 to 5 to minimize the risk of exposure to COVID-19.

Tomb Sweeping Day, during which Chinese pay respect to their ancestors by visiting their graves, falls on April 5 this year.

According to Zeng Qun, deputy head of the bureau, individuals who prefer to visit the graves in person on peak days, which are March 26 and 27 as well as April 2 to 5, will have to schedule an appointment with the cemeteries via official WeChat platforms.