An exterior view of the Phi Kappa Psi fraternity house at the University of Virginia, in Charlottsville, Va., the site of an alleged sexual assault of a student revealed in a Rolling Stone article published online Wednesday. (Ryan M. Kelly/AP)

Faced with mounting pressure from students, faculty and alumni, University of Virginia President Teresa Sullivan suspended all campus fraternities Saturday, an action prompted by a searing magazine account of an alleged 2012 gang rape inside a fraternity house at the school.

The suspension, which includes sororities and other Greek organizations, will continue until Jan. 9, the Friday before the spring semester is to begin, Sullivan said in a statement posted on the university’s Web site.

“In the intervening period we will assemble groups of students, faculty, alumni, and other concerned parties to discuss our next steps in preventing sexual assault and sexual violence on Grounds,” she said, using university parlance for its Charlottesville campus.

Sullivan’s lengthy statement was the most dramatic sign that the 195-year-old university, which prides itself as a bastion of tradition, gentility and honor, was reeling from charges­ that it failed to reckon with a culture of excessive drinking and sexual misconduct on campus.

The article in Rolling Stone magazine, posted online Wednesday, describes a brutal sexual assault that allegedly occurred in the Phi Kappa Psi house. The victim, who was given an alias by the magazine, said a fraternity member led her upstairs during a party and into a dark room, where several men raped her.

On Friday, the magazine published additional accounts from anonymous U-Va. students describing on-campus rapes and an inadequate response from the university officials contacted by the victims.

The university’s Board of Visitors will meet Tuesday to discuss the allegations, as well as policies and procedures on sexual assault, Sullivan said.

One prominent board member, former rector Helen Dragas, posted to the university’s Facebook page to say she had learned that a college friend “had the exact same thing happen to her in a fraternity house.”

“I never knew it,” wrote Dragas, who attended U-Va. in the early 1980s, “and I was really shaken that women were being victimized then, and still are more than thirty years later. This is a serious problem, to say the least. We need to solve it.”

After the suspension was announced, Dragas said in an e-mail that she’d heard “reactions around Grounds ranging from ‘not nearly enough’ to ‘it implies all our sons are guilty.’ ”

Sullivan’s statement came after more than 1,000 students and faculty members signed a letter sent Friday night calling on the president to freeze activities for groups under investigation for sexual assault and for a suspension of Greek-letter organizations throughout the weekend.

Hundreds attended a rally Thursday, and dozens more marched through campus Friday calling for new efforts to combat “rape culture” at the university, according to reports in the student-run Cavalier Daily. On Saturday afternoon, four protesters were arrested for trespassing at the Phi Kappa Psi house, said Lt. Stephen Upman, a Charlottesville police spokesman

“People were unsatisfied with [Sullivan’s] initial response,” said Retsy Holliday, a senior foreign affairs majors who was one of the drafters of the letter. “This was our cry for more action. And she responded.”

The president of the university’s Inter-Fraternity Council, which consists of 31 chapters with about 1,500 student members among them, said Saturday that the suspension would “ultimately benefit our university and the Greek community in the long term.”

President Tommy Reid, a fourth-year student, said he and fellow fraternity leaders learned about the suspension Saturday morning in conversations with the university’s dean of students.

The council had already announced early Saturday that it was voluntarily suspending social activities through the weekend, Reid said, “in recognition of the fragility of the U-Va. community right now, out of respect for the survivors of sexual violence at U-Va.”

“We were in very serious conversations with fraternity presidents about taking similar actions for the rest of the semester,” he said.

Besides the 31 fraternities represented by the Inter-Fraternity Council, the suspension also applies to 16 sororities and 15 minority-oriented Greek-letter organizations organized under other councils, said university spokesman Anthony P. de Bruyn. About 3,500 students are Greek-affiliated, he said.

Sullivan’s announcement came at a particularly active moment on the university’s social calendar, with the last home football game of the Cavaliers’ season held Saturday.

Although the Greek suspension lasts seven weeks, the practical effect is modest. Students are set to leave campus Wednesday for Thanksgiving break, returning for one week of class the following Monday. Final exams are scheduled thereafter through Dec. 16, with classes then recessed until Jan. 12.

Reid said many U-Va. fraternities would typically host holiday dances, parties or fundraisers over the coming weeks that will now be canceled.

The Rolling Stone article has roiled the campus, raising questions among students, faculty members and parents about the way the case was handled by university administrators. Elected officials, including Gov. Terry McAuliffe (D) and Sen. Mark R. Warner (D), expressed deep concern about the allegations, which are under investigation by Charlottesville police.

Sullivan called the account “appalling” and said it “caused all of us to reexamine our responsibility to this community.” Besides the rape allegations, the Rolling Stone article described a seemingly unconcerned response from U-Va. administrators.

“We know, and have felt very powerfully this week, that we are better than we have been described, and that we have a responsibility to live our tradition of honor every day, and as importantly every night,” Sullivan wrote.

She also made her most forceful call to students and alumni to be cooperative in the police investigation: “There are individuals in our community who know what happened that night, and I am calling on them to come forward to the police to report the facts. Only you can shed light on the truth, and it is your responsibility to do so.”

Alex Pinkleton, a junior who said she is a close friend of the victim from the Rolling Stone article, said that students on campus have experienced a range of emotions in the aftermath of the story’s publication.

“There’s been disappointment to intense anger,” Pinkleton said. “Now it’s about how best to take that energy, take that anger towards fraternities and Phi Psi, and taking all of those emotions and turning it into a constructive conversation about sexual assault.”

Pinkleton said she survived a rape and an attempted rape during her first two years on campus. “The party culture on college campuses lends itself to sexual assaults,” she said.

In her statement, Sullivan encouraged the university community to participate in a review of the university’s sexual misconduct policy for students. “Providing candid feedback to this policy is a practical step that you can take to help,” she wrote, “and I hope that you will.”

She also sent a particular message to senior undergraduates on the day of the last home football game — a traditional occasion for the “fourth-year fifth,” in which some seniors drink to particular excess before kickoff: “I hope that you will embrace your role as leaders and demonstrate a renewed sense of responsibility to our community, and a renewed commitment to make that community better. It starts today.”

Phi Kappa Psi, the fraternity implicated in the Rolling Stone article, suspended activities at its U-Va. chapter Thursday. The fraternity’s national leadership said that it would cooperate in the police investigation and that it had launched its own internal investigation into the allegations.

Mrinalini Chakravorty, an English professor, said that the Greek system at U-Va. has run amok for years, contributing to the challenge of addressing sexual assaults on campus.

“The Greek life here is entrenched; it’s been tradition,” Chakravorty said. “The question of how to reform it is a big one.”

One mother of a recent U-Va. graduate from Northern Virginia said that the article left her daughter in tears. The mother said that she could not finish reading the article because “it was too painful.”

She said she believes that not much has changed since she was a student there three decades ago. As a freshman in the fall of 1978, the woman said she was date-raped after a party.

“What is seared into my memory is that he was on top of me, and I was saying, ‘No! No! No!’ ” she said. “I never told anybody. I felt shame and embarrassment. I thought it was my fault because I had gotten myself into that situation.”

The woman said she never reported the rape because she felt vulnerable and alone. The Washington Post generally does not name victims of sexual assault.

The woman said that the university should take responsibility for crimes that occur on campus. “I want to ask them, ‘What if this were your daughter? Or your sister?’ ” she said. “I don’t call myself a victim. I call myself a survivor.”

Michelle Boorstein contributed to this report.