BOSTON (CBS) — Boston University is holding disciplinary hearings for 20 students who attended an outdoor “beer party” on campus over the weekend. The students could be suspended for a semester with no refund for tuition or housing for violating the school’s coronavirus guidelines, the administration said. 

BU police broke up the party in the area known as “the grotto” at about 1 a.m. Sunday after receiving a report of a large gathering with music and alcohol. All the students caught by police were under 21 years old.

“There were 25-plus people with alcohol, close together, with no masks or their masks pulled down around their chin,” Dean of Students Kenneth Elmore said in a statement about the “highly problematic” incident.

Elmore had warned at the beginning of the semester that BU would suspend partying students “who won’t take COVID-19 seriously.”

BU has not had to suspend any students up until this weekend’s incident. Suspended students will not be allowed to continue taking classes, even remotely.

A school hotline set up to receive reports of coronavirus violations has received 187 calls so far, BU said.

“You just can’t have large-scale parties,” Elmore said. “And that’s important, with Halloween coming.”