Authorities in China's southwestern city of Baise have ordered its 3.5 million residents to stay at home and avoid unnecessary travel as they enforce curbs that are among the toughest in the nation's toolbox to fight rising local infections of Covid-19, Reuters reports.

Baise, in the region of Guangxi, has reported 37 domestically transmitted infections with confirmed symptoms in the last 24 hours, up from six the day before, data from the National Health Commission showed.

Residents should stay indoors except for trips to buy essentials or test for Covid-19, and should opt for delivery rather than in-store purchases whenever possible, state television said, citing a statement from the city government.