Lockdowns in major Chinese cities are raising concerns about a slowdown of the world's second-largest economy.
About 1,500 coronavirus cases were confirmed in 24 provinces and autonomous regions in China on Sunday.
In Chengdu in the inland province of Sichuan, all 21 million residents have been under lockdown since Thursday last week. The city said on Sunday night that all citizens will have to take PCR tests between Monday and Wednesday, and restrictions will remain for most of the city.
Restrictions on movements are also in place in other major cities, including Shenzhen, Tianjin and Dalian.
Chinese media are reporting that a total of 33 cities across the country have introduced full or partial lockdowns since last month.
China has adopted a zero-COVID policy, with strict measures to contain the infection.
Concerns are growing that the restrictions will further dampen consumer demand and disrupt supply chains.