BEIJING -- The numbers of confirmed COVID-19 cases and asymptomatic carriers under medical observation in China have seen a fluctuating downward trend in recent 10 days, an official said Thursday.

Some areas have gradually stemmed virus transmissions in communities, marking the return of normalcy in people's lives and production resumption, Mi Feng, spokesperson for the National Health Commission (NHC), told a press conference.

Over 550,000 local infections have been reported on the Chinese mainland in April, said Wu Liangyou, an official with the NHC.

At present, provincial-level regions such as Hebei, Jiangsu and Beijing have taken active and effective measures against the virus, Wu said, adding that epidemic situations in Jilin and Shanghai have continued to improve.

The risk of community transmission in Shanghai has been gradually reduced, Wu said.