BEIJING (AP) — China on Friday ordered a lockdown of the 9 million residents of the northeastern city of Changchun amid a new spike in COVID-19 cases in the area.

Residents are required to remain home and 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.

Just two cases were detected within the city itself, although 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 found 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.