Brown University announced Monday that two fraternities, Sigma Chi and Phi Kappa Psi, have been sanctioned for hosting unregistered parties and facilitating sexual misconduct, the university said in a statement. Both fraternities were linked to sexual abuse complaints filed by female students last October.

The fraternities were found “responsible for holding unregistered parties last fall, creating environments that facilitated sexual misconduct,” the university said, adding that no individual member of either fraternity was accused of sexual misconduct or faced any criminal charges. However, the statement added: “All Brown community members need to be involved in preventing sexual violence, and all student organizations are expected to ensure that adequate security measures are in place to promote safe events and activities.”

Phi Kappa Psi, a fraternity in Sears House, will lose its university recognition for four years, including the loss of housing on campus, with immediate effect, the university announced. Two students had reported that they were given “an alcoholic drink that contained a date rape drug” during an unregistered party hosted by Phi Kappa Psi in October.

Sigma Chi, a fraternity in Olney House, has been placed on probation and its university privileges have been suspended until fall 2016, the university said in a statement, adding that the fraternity will not be allowed to sponsor social events. In October, a student had reported “an incident of non-consensual contact of a sexual nature” that took place as students were leaving the crowded basement of the fraternity.

“These student organizations were found responsible for creating an environment that facilitated sexual misconduct through improperly monitored spaces and inadequate safeguards surrounding the service of alcohol,” the university wrote, in the statement.

A comprehensive review of alcohol policy and regulations for social events was announced by Russell Carey, the university’s executive vice president, and Vice President Margaret Klawunn.