The Central Chinese city Wuhan detected nine positive COVID-19 cases in housing complexes that are under lockdown. The patients have been transferred to designated hospitals for treatment, authorities said Sunday. A total of 11.28 million people have been tested for the COVID-19 virus citywide this week.

A medical worker takes a swab sample from a resident for COVID-19 nucleic acid testing at a residential community in Wuhan, central China's Hubei Province, Aug. 3, 2021. (Photo: Xinhua)

Hubei authorities rolled out citywide testing in Wuhan starting from August 3 after six asymptomatic cases were reported in the city the day before. Contact tracing and nucleic test results show the cases were related to four confirmed cases in Huaian, East China's Jiangsu Province and were transmitted by the Delta variant.