(ITHACA, NY) -- Cornell University announced Monday that it's suspending frat parties after students reported they were drugged and one student alleged being sexually assaulted at a residence off-campus, school officials said.
The school's president, Martha E. Pollack and Ryan Lombardi, the vice president of student and campus life, addressed the suspension in a letter to students on Monday.
Student leaders at the school's Interfraternity Council (IFC), which governs IFC-recognized fraternities at the university, decided to suspend the fraternities on Sunday during an emergency meeting.
On Friday, Cornell University Police issued a crime alert saying that between Sept. 24 and Nov. 3 there were four incidents where students claimed that they drank very little or no alcohol but became debilitated while at the frat parties and said they were "roofied."
"Fraternity leaders will take this time to implement stronger health and safety plans," Pollack and Lombardi wrote. "No IFC-affiliated social events will resume until student leaders and Cornell staff are confident activities can take place responsibly and safely."
According to Cornell police, in a second crime alert, someone reported that they were sexually assaulted on Sunday at a location off-campus.
The Ithaca Police Department is investigating the incident, according to Cornell police.
Ithaca police did not immediately respond to ABC News' request for comment.