China's Shanghai denies lockdown rumours as it nears 1,000 Covid cases

Authorities in the Chinese city of Shanghai have denied rumours of a city-wide lockdown after a sixth straight increase in daily asymptomatic coronavirus cases pushed its count to record levels despite a campaign of mass testing aimed at stifling the spread.

The latest outbreak in China's wealthy commercial hub remains tiny by global standards.

But its testing campaign, with many people locked in residential compounds for days, follows Beijing's national "dynamic clearance" policy to stamp out flare-ups as quickly as possible.

Daily new local COVID-19 infections in Shanghai neared 1,000 on Tuesday, but authorities vowed to stick with a "slicing and gridding" approach to screen neighbourhoods one by one, rather than shut down entirely.

The lockdown rumours triggered panic buying late on Tuesday night, with slots on Alibaba's "Freshhippo" delivery app running out a minute after midnight.

"Please do not believe and spread rumours," the city government said on its Weibo microblog site.

City health official Wu Jinglei said several streets and residential compounds had been unsealed after testing, but some areas face another round on Wednesday and Thursday, as the focus of its efforts is narrowed.