The travel restrictions and closures led Nomura to downgrade China's July-September economic growth forecast, as well as its full-year prediction, saying the zero-tolerance approach to the virus was becoming increasingly costly.

Since late July, the highly transmissible Delta variant has been detected in at least a dozen Chinese cities, including the capital, Beijing, and Wuhan, where the novel coronavirus emerged in late 2019.

China reported 71 new domestically transmitted COVID-19 cases for August 3, official data showed, the highest daily tally since January 30. The number of cases has increased for five consecutive days since July 30.

Most cities have yet to impose strict citywide lockdowns but a few have limited some movements.

Nanjing and Yangzhou in eastern Jiangsu province, where the majority of China's local cases have been reported since July 20, have suspended domestic flights, long-distance shuttle buses, taxis and ride-hailing vehicles from entering and leaving the two cities, and suspended some bus services.

Cities such as Zhengzhou and Jingzhou have locked up some neighbourhoods and limited public transport in areas considered higher-risk.

Wuhan said it aims to test all its 12 million population in just three days to screen out infections. It has closed parts of an economic development and innovation zone.

Many cities with domestic infections have closed tourist sites and shuttered entertainment venues. The southern tourist city of Zhangjiajie has banned residents and travellers from leaving.

Including symptomatic patients arriving from abroad, the number of new cases stood at 96 for August 3, up from 90 a day earlier.

China reported 27 new asymptomatic coronavirus cases, which it does not classify as confirmed cases, compared with 41 a day earlier. No new deaths were reported.

Mainland China had recorded 93,289 confirmed cases by Tuesday. The cumulative death toll was unchanged at 4636.

Australian Associated Press