BEIJING -- Mainland China reported over 1,000 new local COVID-19 infections on Friday, the highest daily count since Beijing contained its first national outbreak in early 2020, driven by a jump in asymptomatic infections amid the spread of the Omicron variant.

The size of the latest outbreak is much smaller than many others outside mainland China, but the increase in the number of cases could add pressure to China's "dynamic-clearance" ambition to curb each transmission as quickly as possible.

China detected 703 domestically transmitted asymptomatic infections for Thursday, according to data from the health authority on Friday, up from 435 a day earlier.

That marks a sharp increase from a daily average of about 10 such cases in the first two months this year, Reuters calculations showed.

Another 397 local symptomatic cases, which China classifies separately from symptomless infections, were reported for March. 10, the National Health Commission said.

"Infections in vaccinated individuals are more likely to be asymptomatic than infections in unvaccinated individuals, and vaccine coverage is now very high in China," said Ben Cowling, an epidemiology professor at the University of Hong Kong.

Around 87% of China's 1.4 billion population have received complete doses for primary vaccination as of late February, and around 40% of the population has received a booster shot.

The city of Qingdao reported over 300 local infections, more than any other among the dozens of cities that reported local cases for Thursday.

There were no new deaths, leaving the death toll unchanged at 4,636.

As of March 10, mainland China had reported 112,940 cases with confirmed symptoms, including both local ones and those arriving from abroad.