A hazing incident at Carleton College involving "extreme alcohol consumption" in connection with a secret club has prompted the private school to suspend 13 students, administrators announced.

A letter sent Friday to students, faculty and staff from Carleton President Steven Poskanzer and another top college official revealed that punishment for the 13 students includes an immediate three-trimester suspension, alcohol education and community service.

"We are greatly troubled by these events" in the early hours of April 28, the letter read. "We are continuing to investigate actions relating to this incident that resulted in harm to college students."

Police also are investigating, according to the college.

The club is not sanctioned by Carleton, a highly regarded liberal arts school of roughly 2,000 students in Northfield that has never had fraternities or sororities.

Poskanzer's letter said that the "event on campus that has severely compromised" the college's fundamental value of mutual respect "involved hazing and extreme alcohol consumption as part of initiation into a secret coed social club."

A school investigation found those responsible violated the student code of conduct that forbids hazing and other actions that threaten the health, well-being, and safety of others.

Also, a news release issued Friday by the school mentioned an alleged sexual assault of a student "following the hazing incident." On Sunday, school spokesman Joe Hargis declined to reveal anything further about the allegation, including how it might be connected to the excessive drinking, other than to say city police are investigating the student's allegation.

Hargis said that college staff knew little about the club. He said students referred to it as DTX, an apparent reference to the Delta Tau Xi fraternity in the movie "Animal House."

The letter did not disclose any details about how the initiation was carried out, nor did it identify the students. It also did not specify the severity of the harm inflicted during the incident. Hargis said that he is unaware of anyone suffering any lingering physical effects.

"The events of April 28 were meticulously planned," read the president's letter, which was co-signed by Carolyn Livingston, vice president of student life and dean of students.

The letter encourages anyone with information to contact Livingston's office at 1-507-222-4075.

"Hazing is a serious problem at colleges and universities around the country," the administrators' letter continued. "Further, we will examine and strengthen our education programs and awareness about hazing and alcohol abuse as we move forward."

Carleton policy does allow students 21 years and older to consume alcohol on campus; however, the entry reads, "Students are expected to make responsible decisions concerning the use of alcohol. The college recognizes and abides by all state laws, and will cooperate fully with civil authorities."

Across town, alcohol is banned at St. Olaf College, also a private liberal arts school. That prohibition includes at any college-sponsored functions, whether on or off campus.

Classes at Carleton end on May 31, with exams the following week and commencement scheduled for June 10.