The number of new local Covid cases in Shanghai has dropped by half to 1,487, from more than 3,000 the day before.

Of the latest infections, 228 showed symptoms and 1,259 were asymptomatic.

"With the efforts from all front, new infections have significantly dropped, and fewer positive cases are found outside quarantine areas. The epidemic risk in society has been effectively controlled. Currently, the trend is stabilising and improving, and the transmission risk has been under control," said Wu Huanyu, deputy director of Shanghai Municipal Centre for Disease Control and Prevention.

"At the same time, it is still the most strenuous and critical moment for our city in achieving dynamic zero. Once we let our guard down, the epidemic may rebound, so it is necessary to maintain and implement prevention and control work."

The financial hub, which is still battling the country's biggest coronavirus outbreak, reported seven Covid-related deaths as well on Tuesday.

Health authorities said all seven were elderly people who had been chronically ill.

Elsewhere, the number of symptomatic Covid cases in Beijing fell to 24 from 61. The capital also reported 13 more asymptomatic infections.

The National Health Commission reported a total of 302 local symptomatic and 1,545 asymptomatic infections across the mainland.