(NewsNation) — A number of fraternities at the University of Southern California have severed ties with the school over the imposition of new rules following allegations of widespread sexual assault at parties last fall.

Fraternities had until Friday to decide if they planned to comply with the new rules, which focus on increased security at frat houses and sexual violence prevention for students, CBS Los Angeles reported. The rules also called for a delay in the “rush” recruitment period, which would begin in January instead of the fall semester.

Kappa Alpha Order, Pi Kappa Alpha, Sigma Alpha Mu, Sigma Chi, Tau Kappa Epsilon and Zeta Beta Tau were among those that chose to disaffiliate, which means the groups won’t be able to participate in campuswide events. The university suspended all fraternity activities last year after allegations of sexual assault and drugging at parties surfaced.

In a statement on Instagram, the university said it was disappointed in the fraternities’ decision to follow a “national trend.”

“This decision seems to be driven by the desire to eliminate university oversight of their operations,” the statement read. “The members are chafing at procedures and protocols designed to prevent sexual assault and drug abuse and deal with issues of mental health and underage drinking.”

The newly formed University Park Interfraternity Council maintained its members are committed to student safety and chastised the university for creating a “largely unworkable” relationship.

“These actions put considerable stress on the continuing viability of all of the chapters and reaffirmed that USC has not committed the resources and focus necessary to a well-functioning Greek community,” the group said in a statement on Instagram.

Last year, USC President Carol Folt acknowledged a delay in the reporting of the alleged crimes to the campus community, even after multiple reports were received.