SHANGHAI (Reuters) - The sprawling district of Minhang in central Shanghai has implemented new lockdown measures to detect and control COVID-19 transmission risks, the district government said on Thursday.

       The district, home to more than 2 million people, will conduct nucleic acid tests for all of its residents on June 11, and restrictions will be lifted once the testing is completed, the government said on its WeChat account.

       Shanghai reported four new confirmed symptomatic COVID-19 cases on Wednesday, all in zones already under quarantine. None of the new cases were in Minhang district.

       Shanghai emerged from a strict two-month lockdown last week, though some residential compounds have been sealed off again as authorities continue to pursue a "dynamic zero-COVID" policy aimed at shutting down transmission chains as soon as possible.

       (Reporting by David Stanway; Editing by Stephen Coates)