SEATTLE (AP) — Officials say COVID-19 cases continue to climb at University of Washington sorority and fraternity organizations in an outbreak reported last week.

As of Monday morning, 163 people at a dozen sororities and fraternities have tested positive for COVID-19, University of Washington spokesperson Victor Balta said on the university website.

Students in the Greek community who have tested positive or have COVID-like symptoms are being told to isolate at their residences, the post said. The university is not aware of any students who have been hospitalized or have reported severe symptoms.

Others who may have been exposed to positive cases, as well as members of fraternities and sororities with positive cases, are also being asked to isolate and get tested. Balta has said the university is working with Public Health – Seattle & King County to contain the outbreak.

The outbreak was first reported Thursday with 104 cases at nine fraternities and sororities.

Public health officials said last week it’s another sign that people need to remain vigilant about the coronavirus. Dr. Jeff Duchin, head of Public Health – Seattle & King County, said cases in the county were up last week compared with the previous week.

During the summer, an outbreak in the same Greek community totaled 154 positive COVID-19 cases identified over about a month.

A COVID-19 outbreak in late August was tied to Washington State University in Pullman as students returned for the start of the school year.