Shanghai recorded a steep climb in Covid-19 cases as spreading anxiety in the Chinese city of about 25 million prompted panic-buying at supermarkets.

Millions endured a second day of lockdown after authorities effectively split the country's biggest urban area in two, with residents of the city's eastern half confined to their homes for four days and subjected to mandatory testing, AFP reports.

China reported 6,886 domestic Covid cases nationwide, with more than 4,400 of them detected in Shanghai, now the centre of the country's worst Covid-19 outbreak since the early days of the pandemic.