Shanghai, China’s largest city, has said it will impose a fresh round of lockdowns in an effort to combat a new wave of coronavirus cases. Authorities on Sunday night announced a plan to test all 26 million residents in two stages over nine days. Shanghai had previously avoided imposing a citywide lockdown—unlike other cities including Xi’an and Shenzhen—preferring a “slicing and gridding” approach that saw neighborhoods be screened day by day. Officials began balking, however, as daily recorded cases began to spike, soaring to a new height of more than 2,600 on Sunday. The local government asked citizens to treat the restrictions seriously, imploring them on WeChat to “support, understand and cooperate with the city’s epidemic prevention and control work,” according to the BBC. The staggered, two-phase lockdown will allow the city, considered China’s financial hub, to remain at least partially functioning over the next week and a half, government officials said.