The University of Arizona has suspended a fraternity’s activities after a female student alleged two men sexually assaulted her at the fraternity’s house in August.

The Sigma Phi Epsilon chapter at the southern Arizona school was already on probation, but the university said it has now imposed an activities suspension, stating the fraternity poses a risk to the university community. An investigation into the allegations continues.

“It has been determined that your organization presents a substantial risk to members of the university community,” said Associate Dean of Students Whitney Mohr in a letter sent to the fraternity on Wednesday.

The local chapter did not respond to calls or emails, but the national fraternity organization said it had ordered members of the Arizona chapter to comply with any investigation.

“Sigma Phi Epsilon does not tolerate sexual assault or sexual misconduct.…