The southwestern metropolis of Chengdu on Tuesday reported no new locally transmitted Covid-19 infections on September 19, when millions of people emerged from a coronavirus lockdown that had closed schools, disrupted businesses and forced residents to stay home for over two weeks.

The figure is down from two infections a day earlier, city government data showed.

With a population of 21 million, the southwest metropolis is the largest mainland city to shut down since global finance hub Shanghai imposed a two-month lockdown in April.

"With the joint efforts of the whole city, the epidemic has been effectively controlled," the Chengdu government said in a statement on Sunday.

Government departments, public transport services and companies were able to resume work on Monday, the statement said, after shutting down on September 1.

Chengdu will continue to conduct mass testing, and anyone who wants to enter a public area or take public transport will require a negative Covid test result within 72 hours – similar to the rules in other large cities including Beijing and Shanghai.

Schools will re-open in an "orderly manner" and returning students will be strictly tested, the statement said.

Gyms, swimming pools, mahjong clubs and other indoor entertainment venues must all check whether patrons have a negative test result within 48 hours.

Chengdu will host the world team table tennis championships at the end of September in a "closed-loop" bubble that will be China's first international sports event since the Beijing Winter Olympics and Paralympics in February and March. (Agencies)