(Reuters) - Three women sued Yale University and nine fraternities on Tuesday, saying the off-campus clubs harbored a culture of sexual discrimination and assault, and asked the court to order the all-male social organizations to admit women.

FILE PHOTO: Students walk on the campus of Yale University in New Haven, Connecticut, October 7, 2009. REUTERS/Shannon Stapleton

All three undergraduate students of the Ivy League college said they were groped at parties held at fraternity houses during their first semesters at the school, according to the complaint filed in federal court in New Haven, Connecticut.

Ry Walker, a 20-year-old college junior from New York, said someone had pulled up her skirt and grabbed her crotch at a dark and crowded party in 2016, but she did not report the incident because she did not see who had groped her. She said she later realized many Yale women had had similar experiences.

“This sort of normalized groping is still groping and it’s still sexual assault,” Walker said in an interview on Tuesday.

Joan Gilbride, the attorney representing the fraternities in the lawsuit, called the students’ accusations “baseless and unfounded.”

The women said the fraternities discriminated against them by rejecting them on the basis of gender, a decision they said potentially denied them access to networking opportunities that could help their later careers.

Similar organizations for women called sororities do not present the same opportunities, Walker said.

U.S. college fraternities been under fire for years as disturbing stories of alcohol-fueled partying, sexual assault and “hazing” of potential new members have come to light. In 2017, Penn State student Tim Piazza died after tumbling down stairs drunk during a hazing event, sustaining injuries that prosecutors said fraternity members ignored.

Supporters of Greek life said the incidents that have made the news do not define fraternities.

“The stories are focusing on a small percentage compared to the hundreds of thousands of fraternity members and thousands of chapters out there,” Todd Shelton, a spokesman for the North American Intrafraternity Conference said.

Fraternities raise more than $20 million each year and volunteer countless hours in their communities, he said.

Yale spokesman Thomas Conroy declined to comment on the lawsuit.

He forwarded a January message sent to students by the school’s dean about a university investigation that found evidence of sexual misconduct at one of the nine fraternities targeted in the lawsuit.

“I condemn the culture described in these accounts; it runs counter to our community’s values of making everyone feel welcome, respected, and safe,” Dean Marvin Chun said in the message. “I also offer some plain advice about events like these: don’t go to them.”