China on Friday ordered a lockdown of the nine million residents of the north-eastern city of Changchun amid a new spike in Covid-19 cases.

Residents are required to remain home, with one family member permitted to venture out to buy food and other necessities every two days.

All residents must undergo three rounds of mass testing, while non-essential businesses have been closed and transport links suspended.

China reported another 397 cases of local transmission nationwide on Friday, 98 of them in Jilin province that surrounds Changchun, a centre of the country’s auto industry.

In the entire province, cases have exceeded 1,100 since the latest outbreak first struck late last week.

Just two cases were reported within Changchun itself on Friday, bringing its total to 78 in recent days. Authorities have repeatedly pledged to lock down any community where one or more cases are found under China’s “zero tolerance” approach to the pandemic.

Another 93 cases were confirmed in the nearby city of Jilin that bears the same name as the surrounding province. Authorities have already ordered a partial lockdown in the city and severed travel links with other cities.