A high-rise in the neighborhood of Sindorim was closed and disinfected late Monday after workers at a call center on its 11th floor were confirmed as patients, according to Guro Ward, which oversees Sindorim.

In a meeting with provincial officials, Seoul Mayor Park Won-soon initially said 64 cases occurred from the outbreak, although numbers released later in the day by local governments estimated around 80 infections.

Wards in Seoul reported close to 60 confirmed cases in their areas. Incheon and Gyeonggi Province each confirmed more than 10 cases.

The KCDC, which only officially confirmed 50 cases, said all diagnosed employees worked on the 11th floor and did not wear masks.

But numbers are feared to further soar, considering the usually packed work environment at call centers, where temporary workers are outsourced to respond to customer complaints and inquiries.

Call center employees usually have to work in narrow booths and in the case of those working for financial firms, have to work in designated areas, as they handle personal information.

Health authorities said they plan to also check 550 other employees at the call center who worked on the seventh to ninth floors of the same building, with Seoul and other local governments all scrambling to screen people who have come in contact with workers as soon as possible while asking those at most at risk to isolate themselves.

Incheon said that it has identified some 60 people with ties to the call center, with Uijeongbu in Gyeonggi, just north of Seoul, reporting its first infection case from a person who works at the Guro center. Gyeonggi has determined that 45 people came into contact with call center workers. (Yonhap)