Students queue for COVID-19 tests at a stadium of Qingdao University in Qingdao, east China's Shandong Province, Oct. 13, 2020. (Xinhua/Li Ziheng)

QINGDAO, Oct. 16 (Xinhua) -- Qingdao, a coastal city in east China's Shandong Province, has completed a citywide nucleic acid testing covering all its 11 million residents starting Monday, after a new cluster of local COVID-19 infections emerged.

As of 8 a.m. Friday, over 10.16 million of the collected samples had been tested, and results showed no new positive cases, Xue Qingguo, Qingdao's deputy mayor told a press conference, adding that the results of the remaining samples will be released by 6 p.m.

The re-emerged infections have led to 13 new confirmed cases by Thursday. Inappropriate disinfection in the CT room at the Qingdao Chest Hospital was believed to be responsible for the infections.