Unlike other major economies, Beijing has dug in its heels on a zero-Covid approach of stamping out clusters as they emerge, though this has become increasingly difficult with the infectious Omicron variant.
The painful coronavirus curbs in major Chinese cities run counter to trends seen in the rest of the world, which has largely moved towards co-existing with the virus even as infections spread.
The two major cities were among several places in China that implemented curbs to stop the spread of the Omicron wave during March to May, with Shanghai imposing a two month-long city-wide lockdown that lifted on June 1.
After originally taking a more piecemeal approach aimed at minimising economic disruptions, Shanghai imposed broader restrictions last week as authorities struggled to contain what has become the city's biggest COVID-19 outbreak.
China's financial hub of Shanghai continued to report a spike in cases, with companies in the country struggling to maintain output amid stringent curbs.
The snap lockdown, announced by Shanghai's city government on Sunday, will split the city in two roughly along the Huangpu River for nine days to allow for "staggered" testing. It is the biggest COVID-related disruption to hit the city.
Since March, a patchwork of restrictions has kept most of the city's 25 million residents confined to their homes or compounds, with daily caseloads regularly edging over 25,000.
While China’s largest city has seen progress in controlling the COVID-19 outbreak, any relaxation in prevention and control measures could allow it to rebound, deputy director of Shanghai’s Center for Disease Control Wu Huanyu told reporters.
That compared with 5,656 new asymptomatic cases and 326 new cases with symptoms reported a day earlier. Shanghai on Sunday announced a two-stage lockdown of the city of 26 million people to carry out COVID-19 testing.