Updated at 1:49 p.m.

Residents at two Greek life houses at the University of Maryland are quarantining after at least four tested positive for coronavirus. Cases have surged at the College Park school in recent days.

Since the fall semester began Aug. 31, the university has identified 85 new cases of the virus among students, faculty and staff. Another 75 unverified cases have been self-reported by individuals who have been on or near the campus in the past two weeks. More than one-fifth of quarantine-designated housing units are occupied.

Classes for undergraduates, who are allowed to live on campus, are online-only through at least Sept. 14.

On Aug. 29, one Phi Delta Theta fraternity house resident tested positive, according to school newspaper The Diamondback. Two dozen other residents were tested off-campus, with two additional residents testing positive. While about five are quarantining in the residence, others are in an alternate isolation space, the publication reports.

One resident has also tested positive at the Sigma Kappa sorority house, and all residents are now quarantining at the residence or alternate locations, according to The Diamondback.

Last week, the school suspended 19 students for failing to adhere to its protocols around COVID-19 safety.

Andrea Goodwin, the director of the Office of Student Conduct, said in an email to students Friday that the number of coronavirus cases had increased despite “the majority” of students following guidelines.

“This can largely be attributed to a failure by some to comply with 4 Maryland expectations, in particular gathering in large groups, failing to wear masks and failing to maintain 6 feet of physical distance from others and, at times, to the reckless disregard for the directives of the medical professionals at the University Health Center that those infected with the virus isolate themselves so they do not infect others,” Goodwin wrote.

The school — located in Prince George’s County, home to the highest tally of positive cases in the state — also temporarily put the brakes on its athletic training after nearly 10 percent of 501 student athletes tested returned positive results. Student-athletes will be retested Tuesday and the university will determine whether to resume training. Starting Sept. 14, the university will also conduct campuswide testing for three consecutive weeks.

“Our decisions will continue to be based on the data, and informed by public health officials, to prioritize the health and well-being of our campus community,” a university spokesperson said in an email to DCist.

The university has administered more than 19,000 free COVID-19 tests for students, faculty and staff this summer, she says.

This post has been updated with additional information from the university.