China's financial hub Shanghai on Tuesday reported a fifth consecutive daily record for locally transmitted COVID-19 asymptomatic cases as the highly infectious Omicron variant complicates efforts to stop the virus spreading.

Shanghai reported 865 domestically transmitted asymptomatic infections for Monday, official data showed, up from 734 a day earlier.

Shanghai also reported 31 new local cases with confirmed symptoms, which China counts separately, on Monday, including one person who was initially reported as asymptomatic infection and showed symptoms later, according to data from the National Health Commission (NHC).

The infection uptick is small compared with those in many outbreaks overseas, but comes as Shanghai bids to double-down on efforts to follow China's "dynamic-clearance" policy that aims to curb each flare-up, continuing the city's mass testing scheme block by block after having completed more than 30 million tests.

Including Shanghai infections, mainland China reported on Monday 2,281 new locally transmitted cases with confirmed symptoms, the NHC said, compared with 1,947 a day earlier.

The majority of the new cases were found in the northeastern province of Jilin.

The number of new local asymptomatic cases stood at 2,313 compared with 2,384 a day earlier.

There were no new deaths, leaving the death toll at 4,638.

As of March 21, mainland China had reported 134,564 cases with confirmed symptoms, including both local infections and those arriving from outside the mainland.