Inappropriate disinfection at a hospital has led to a new coronavirus cluster in China's city of Qingdao in Shandong province, a local health official said today.

Two stevedores who had handled imported frozen seafood at the port of Qingdao were diagnosed as asymptomatic Covid-19 cases on September 24, reports Xinhua news agency.

They were isolated at the Qingdao Chest Hospital and underwent CT scans.

Due to improper disinfection, the CT room was contaminated and the virus further infected other people, Ma Lixin, deputy Party chief of the provincial health commission, said at a press conference.

Ma also noted that the new cluster infection was neither caused by nor has caused cross-infection in the community.

A total of 13 new coronavirus cases was reported in this new wave of infections by Thursday.

Meanwhile, Qingdao has completed a citywide nucleic acid testing covering all its 11 million residents.

As of 8 a.m. on 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.

Although the Covid-19 originated last December in China's Wuhan city, the capital of Hubei province, China now accounts for only 91,359 cases, while the US (7,977,097) and India (7,307,097) are currently the two worst-affected countries in the world.

China's death toll stands at 4,739..