Shanghai city detected three domestically transmitted COVID-19 cases with confirmed symptoms for November 25, official data from the National Health Commission (NHC) showed on Friday.

The last local symptomatic infection in Shanghai was reported in August.

The new infections came just days after China contained its biggest outbreak caused by the Delta variant.

National health officials had said earlier this month that China's aim was not to remain at zero infections but to make sure local clusters were detected and contained as quickly as possible.

Shanghai has suspended travel agencies from organising tourism that involves trips between the city and other province-level regions.

The financial hub of 24.9 million residents has sealed up a few residential compounds deemed of higher infection risk and a number of local hospitals have halted some face-to-face services to comply with COVID-19 control.

Beijing city's annual marathon was cancelled, its organising committee said on Friday, citing concerns of virus transmission risk, without referring to latest cases.

The committee said last month that the event, previously scheduled at around end-October, had been delayed indefinitely when local cases spread in China's capital.

Beijing city has not reported a locally symptomatic case since November 15.

Xuzhou city in the eastern Jiangsu province, about a nine-hour drive from Shanghai, reported one locally transmitted asymptomatic carrier for November 25, who was a close contact of a Shanghai infection.

China counts asymptomatic cases separately.

Xuzhou - a city of 9.1 million people - has suspended its three subway lines, cut some city-wide as well as long-distance bus services and closed a few entrances on highways linking it and surrounding areas.

It advised residents not to leave town for unnecessary reasons and demanded suspensions of larger face-to-face public activities including concerts, sports events and exhibitions.

Australian Associated Press