People wearing protective face masks are seen at a street market in Wuhan, the Chinese city hit the hardest by the coronavirus disease (COVID-19) outbreak, in Hubei province, China, May 14, 2020. (Photo: Reuters/Aly Song)

SHANGHAI: China's Wuhan said on Friday (May 15) it has tested more than 3 million of its 11 million citizens for COVID-19, as it seeks to test all residents after a cluster of new cases raised fears of a second wave of infections.