Image copyright Grace Dumdaw Image caption The protesters say fraternities have too much power on campus

Two fraternities at a US college have disbanded after leaked meeting minutes that referred to buying date rape drugs and a "rape attic".

Students had staged sit-ins at Swarthmore College in Pennsylvania, calling for Phi Psi and Delta Upsilon to be banned from campus.

College president Valerie Smith said the frats had agreed to disband but that an investigation would continue.

"As a community, we have much healing to do," she added.

Fraternities are exclusive, mostly all-male student organisations. Some are based on areas of study, professions, academic credentials, or on specific religious or ethnical backgrounds. Others serve more of a social purpose.

Last month two student publications - The Phoenix and Voices - published what are alleged to be internal documents from the Phi Psi fraternity.

The redacted, 117-page documents include "meeting minutes" and details of pledging rituals from 2012-16. They feature racist, misogynistic and homophobic language and accounts of physical and sexual assaults, and bravado about buying "date rape" drugs.

The "minutes" also allege that Delta Upsilon "have both a rape tunnel AND a rape attic (gotta choose one or the other)".

Allegations of sexual assault, violence and harassment have also been shared by students on an anonymous Tumblr page named "Why Swarthmore's Fraternities Must Go."

What has the college said?

In her statement, Ms Smith said that an investigation ordered into the fraternities would continue, despite the two groups having disbanded.

"We have heard heartbreaking stories from students who feel unwelcome to the point of wanting to transfer out of our community," she said.

"Those stories have come from across the spectrum of our student body - from student protesters to fraternity members. Stories such as these reflect our failure to realise the values we so often espouse."

She added that "at this time, we have no evidence that any current student participated in the behaviours documented in those materials", but that they would be analysed by an external investigator.

When did students start protesting?

Student protesters began occupying Phi Psi's on-campus fraternity house and camping outside on Saturday.

Organizing for Survivors (O4S) and the Swarthmore Coalition Against Fraternity Violence, which arranged the protest, called on Swarthmore to terminate the leases of both fraternities and ban them from campus.

Instead, they want the properties to be designated for "marginalised" students groups like women and ethnic minorities.

What are the protesters saying?

Fraternities are the only student groups able to lease property on campus. Many members also play in college sports teams, and alumni are often important donors for fundraising campaigns.

Organiser Morgin Goldberg, 22, told the BBC that this had given fraternities "undue social power that they not only hold, but abuse".

Ms Goldberg says she has witnessed harassment, racism and homophobia by members.

"If any other student group had this way of conduct, they would be off campus in 10 seconds," she added.

"Isolating a few bad apples will not address the structure," said Ms Goldberg.

"This is the start of the conversation, not the end of it, about social life at college and which students groups are represented and which are under the bus".

What did the fraternities say?

Phi Psi, which is not affiliated with the national umbrella group for fraternities, was suspended from Swarthmore in 2016 for violating its alcohol and drugs policy. It reopened for parties a year ago.

In a statement, the group said language used in the leaked documents "[was] not representative of who we are today".

"All our current brothers were in high school and middle school at the time of these unofficial minutes, and none of us would have joined the organization had this been the standard when we arrived."

Delta Upsilon fraternity told Philadelphia Magazine that it read the documents "with total revulsion" and said they "do not reflect the values" of the group.