China locks down 21 million in Covid-19 outbreak

Residents are screened for Covid-19 in Chengdu (Chinatopix Via AP)

Chinese authorities have locked down Chengdu, a southwestern city of 21 million people, following a spike in Covid-19 cases.

Residents have been ordered to stay at home, and about 70% of flights have been suspended to and from the city, which is a major transit hub in Sichuan province and a governmental and economic centre.