Around nine million people were to be tested for COVID-19 after a number of new cases were discovered in the Chinese city of Qingdao.
Twelve cases of the virus had been detected on October 12 prompting officials to announce city-wide testing over five days, according to Chinese media reports.
Three million test samples had been collected and tested by October 13, according to officials.
Video from a resident of Qingdao shows long lines of people waiting to be tested.
Health officials said the new cases breaks a two-month streak of no new locally transmitted cases of coronavirus in China.
COVID-19 was first officially reported in the Chinese city of Wuhan in January. Credit: 阿星是个小狼狗哎 via Storyful