Five former University of Mary Washington female students and a feminist empowerment group have filed a lawsuit against the school alleging that administrators fostered a sexually hostile environment on campus.

The lawsuit, filed last week in federal court in Virginia, alleges that beginning in 2014, the students, members of a group known as Feminists United, were subjected to sexual harassment on the Fredericksburg campus and violent threats through a social media platform known as Yik Yak.

The women filed a gender discrimination complaint with the U.S. Education Department’s Office for Civil Rights (OCR) that has been under investigation since October 2015. The women claimed that university officials did nothing to protect the members of Feminists United from anonymous attacks on Yik Yak. OCR enforces the 1972 law known as Title IX, which prohibits sex discrimination in federally funded education programs.

Debra Katz, a lawyer representing the students, said that the women decided to head to court after it appeared the Title IX complaint was stalled and they were being “stonewalled” by officials at the Education Department.

A spokesman for the department said this week that the case is ongoing. A university spokeswoman said officials are reviewing the suit.

“The bigger picture is that students shouldn’t have to go to court,” Katz said. “That’s the purpose of OCR.”

The women, Paige McKinsey, Julia Michels, Kelli Musick, Jordan Williams and Alexis Lehman, are joined in the suit by the Feminist Majority Foundation, a nonprofit group based in Arlington.

The Mary Washington students said they faced vitriolic harassment from anonymous commenters on Yik Yak. The mobile app, once wildly popular on college campuses, has since been shut down.

According to the lawsuit, the attacks on Yik Yak made the women feel unsafe.

“Due to this sexually hostile environment, Plaintiffs suffered emotional and psychological harm that, in some cases, required professional treatment,” the suit said. “By choosing to permit the harassment to go unaddressed and unpunished, and, thereafter, choosing to allow the escalated attacks to proceed without consequence, defendant UMW became liable for the acts of retaliation against the Plaintiffs and responsible for the clear and direct violation of the Plaintiffs’ rights under and pursuant to Title IX.”

Mary Washington is a public liberal arts university with about 4,600 students.

Anna Billingsley, an associate vice president at the school, said the university took several measures to address issues raised when the women filed their complaint in 2015. She said the school hired a Title IX investigator, formed a sexual assault task force and implemented a new awareness training program for all faculty, students and staff members.

“We took a number of steps that we felt created a much safer and secure campus and we are continuing to address concerns related to sexual violence,” Billingsley said. “Our eyes were opened and we worked diligently to meet the needs of the students.”