— A "credible and serious security threat" was a primary reason that Duke University officials on Thursday abandoned plans to allow Muslim students to start broadcasting a weekly call to prayer from the Duke Chapel tower, a spokesman said.

The university announced plans Tuesday for members of the Duke Muslim Students Association to start the three-minute weekly call or chant, known as adhan or azan, on Friday afternoon.

The decision caused a national furor, with Franklin Graham, the son of evangelist Rev. Billy Graham and the head of the international relief organization Samaritan's Purse, posting on his Facebook page that followers of Islam are "butchering" people who don't share their beliefs and urging Duke alumni and supporters to withhold donations.

In a Thursday interview with WRAL News, Graham refused to back down, even for those Muslims who have condemned radical Islamic actions.

"I don't feel I owe an apology to anybody. I think Duke University, they owe an apology," he said. "They're the ones who owe the apology to Christian students and the ones who donated money for the chapel."

Michael Schoenfeld, Duke's vice president for public affairs and government relations, said Thursday that the call to prayer would take place in a quad outside the chapel.

“Duke remains committed to fostering an inclusive, tolerant and welcoming campus for all of its students,” Schoenfeld said in a statement. “However, it was clear that what was conceived as an effort to unify was not having the intended effect.”

Muslim students have used the chapel basement for prayers for several years, he said, and most of the prayers would continue in the basement after the initial call in the quad, which he said is used for many interfaith activities.

More than 700 of Duke’s 15,000 undergraduate and graduate students identify themselves as Muslims.

"No one is saying they can't worship their God," Graham said, adding that he disagreed with using the bell tower and a microphone to broadcast the chant.

"You're taking that bell tower, and you're turning it into a Muslim minaret," he said. "I think it's a slap at the Christian faith."

In majority-Muslim countries across the globe, the adhan is broadcast from mosques and on television and radio stations five times a day to correspond with prayer times. On Fridays, the day of worship in Islam, sermons are also broadcast.

In the United States, amplified adhan exists in a handful of communities.

Khalilah Sabra, executive director of the Muslim American Society in Raleigh, called Duke's reversal "a terrible shame," saying it's unfair for Graham and others to blame all Muslims for the violent acts of a few.

"Duke took a coward's way out and cannot pretend to be advocates of diversity. This was primarily because it caved into the fallout nourished by racism," Sabra said in an email to WRAL News. "A huge gap could have been bridged; now it may remain broken."

Graham applauded Duke's choice not to allow the Islamic call to prayer from the bell tower, calling it "the right decision."

Ibrahim Hooper with the Council on American-Islamic Relations disagrees.

"It sends a message of intolerance," he said. "It sends a message that Duke is willing to bow to bigotry and intolerance. The American Muslim community feels targeted by this Islamaphobia we see online, on newspapers, on TV."

The North Carolina Council of Churches supported Duke's effort to allow the call to prayer from the bell tower, saying it would only help everyone's faith.

"Our understanding of other faiths grows stronger through discussion and interaction, and our own faith is deepened," council Executive Director George Reed said in an email to WRAL News. "Why wouldn’t they encourage prayer within the university community? Why wouldn’t they foster interfaith dialogue? Why would anyone challenge that?"

Many people did, however. Schoenfeld said Duke received numerous negative calls and emails about allowing the Islamic call to prayer, and Durham police said the university had requested extra security Friday afternoon – before officials moved the activity to the quad.

Students and university administrators said they still support efforts to preach diversity on campus.

“Our Muslim community enriches the university in countless ways,” Schoenfeld said. “We welcome the active expression of their faith tradition – and all others – in ways that are meaningful and visible.”

"Every religion has had ups and downs. Every religion has had violence associated with its history," student Akshay Save said, calling it unfair to stigmatize Islam. "This is what we're taught, to embrace diversity."

"It’s not really a way of showing love or loving one’s neighbor by not allowing it to happen. By allowing it to happen could be a stronger message of acceptance and love," student Nathan Bullock said.

"Duke is a higher institution, and you would expect diversity of opinion and debate, but given the raw sentiment and recent events, it is having a different reaction," said Rolin Mainuddin, an associate professor of political science and Western religion at nearby North Carolina Central University.

Mainuddin, who is Muslim, said Duke had to consider the effect of its decisions on fundraising.

"It’s a private university, so the pressure will be stronger than a public university," he said.