Students attend a vigil on Tuesday, a day after an attack at the Ohio State University campus in Columbus, Ohio. Investigators are looking into whether a car-and-knife attack at the university that injured several people was an act of terror by a student. (AP Photo/John Minchillo)

COLUMBUS, Ohio — Holding red and white carnations and swaying, arm-in-arm, Ohio State students sang their alma mater at an interfaith gathering of Muslims and Christians late Tuesday, a moment of reflection after violent chaos.

A day had passed since a student intentionally drove a car into a crowd and began slashing bystanders with a butcher knife before police shot and killed him. Abdul Razak Ali Artan, a young Somali refugee who had joined the college as a junior just three months earlier, stunned the community with a terrorist-style attack, again highlighting festering tensions about Islam and Muslim immigrants in U.S. society.

FBI officials said Wednesday that they believe Artan’s attack was inspired by the Islamic State and the radical Al Qaeda cleric Anwar al-Awlaki, fueling concerns about self-radicalized terrorists and the almost impossible task of detecting and preventing such attacks on U.S. soil. Investigators believe that no one else was involved in the planning of the attack and that it appears he was radicalized online, espeically by Awlaki’s sermons.

Rep. Adam Schiff (D-Calif.), who was briefed by law enforcement officials Wednesday, said that shortly before the attack Artan referred to Awlaki as “our hero” in a post on Facebook. Awlaki was killed in a U.S. drone strike in Yemen in 2011.

Artan’s family members had not noticed any signs of radicalization, Schiff said: “Either he kept it very quiet or there was something that moved him very quickly from being a consumer of radical propaganda to acting out violently. What set him off we don’t know.”

Schiff said it might just be another case of “an alienated young man who is seeking meaning in his life, and is seeking something to belong to, and is attracted by this virulent and violent Awlaki propaganda.”

Artan, who authorities believe was 20 years old, had told a student journalist on the first day of classes in August that as a Muslim immigrant — originally from Somalia and later living in Pakistan — he was concerned about then-candidate Donald Trump’s position on Islam and immigration, bemoaning the fact that many Americans don’t understand the faith and improperly stereotype Muslims. He told Ohio State junior Kevin Stankiewicz, a reporter for the Lantern, that people should travel more to gain an understanding of different cultures rather than rely on misconceptions.

“I found a thoughtful, engaged guy, a Muslim immigrant who wanted to spread understanding and awareness while expressing muted fears that U.S. society was becoming insular and fostering unfair stereotypes of his people,” Stankiewicz wrote in a piece in The Washington Post, describing the Aug. 23 interview. “He was measured and intellectual, not angry or violent.”

Abdul Razak Artan was shot and killed after an attack on the Ohio State University campus in Columbus, Ohio. He is shown in this undated photograph from The Lantern. (Kevin Stankiewicz via The Lantern) Abdul Razak Ali Artan was shot and killed after an attack on the Ohio State University campus in Columbus, Ohio. He is shown in this August 2016 photograph from the Lantern.
(Kevin Stankiewicz via The Lantern)

How Artan morphed from a thoughtful new member of the campus community to someone who wanted to kill indiscriminately is unclear. Authorities confirmed that Artan was a Somali refugee who had come to the U.S. by way of Pakistan, but investigators had not found evidence of actual connections to or direction by terror groups abroad.

Authorities say Abdul Razak Ali Artan, who carried out an attack at Ohio State University, may have been inspired by Islamic State and the late al Qaeda-linked cleric Anwar al-Awlaki. (Reuters)

President-elect Trump tweeted Wednesday morning that Artan was a “Somali refugee who should not have been in our country.”

For Ohio State leaders, the unity event Tuesday in the cavernous St. John Arena offered an opportunity to begin to heal divisions that came into stark relief after the attack.

“I know the past day and a half has been difficult for everybody,” said Javaune Adams-Gaston, senior vice president for student life. “We are hurting. . . . But remember we are stronger together.”

To those who knew Artan as a quiet Somali refugee with a mild demeanor, questions remained in the tightknit immigrant community about how Artan could have become radicalized on his own, drawing almost no notice. Ameer Kader, 31, said that he was on friendly terms with Artan, whom he saw on occasion during prayers at a west Columbus mosque and around town.

“He spoke to me in such a respectful and gentle manner,” Kader said. “He’d ask about my family and say ‘may Allah bless you brother.'”

Kader said that the attack seemed entirely out of character for Artan. Kader said he’s suspicious about official accounts of the attack that correlate Artan’s motivation for the assault with his religious views.

“They make it seem like he’s a Muslim so he must be a terrorist,” Kader said. “They always label Muslims and terrorists together. It’s unfair and it’s a problem. It doesn’t show the true image of Islam. It’s so biased it’s sickening. We reject any acts of terrorism, violence or hatred.”

While the Islamic State claimed Artan as a “soldier,” for the extremist group, Muslim students and city residents openly rejected the violence and denounced links between their religion and terrorism.

Horsed Noah, executive director of the Abubakar Assidiq Islamic Center in west Columbus, said that the campus attack has rattled the mosque’s faithful at a tumultuous time for Muslims in America.

“We’re dealing with a globalized phenomenon of Muslims being looked at with suspicion,” Noah said. “Muslims today are really concerned.”

When word came that an attack had occurred at the Ohio State campus, Noah said his worst fears were realized: “The first thing that came to my mind was, ‘I hope he’s not a Muslim.'”

But then Noah learned that not only was Artan a Muslim but also among the mosque’s 2,000 congregants from the area’s  Somali community. “That shocked everyone,” Noah said, noting that he did not know Artan, whose family lived a half-mile from the mosque. The cause for concern in the age of social media, Noah said, is that those who are vulnerable “can get radicalized in their bedrooms.”

Jibril Mohamed, an Ohio State lecturer on Somali language and culture, said that he’s worried Trump’s comments will stoke fear among Somali refugees and possibly cause backlash against immigrants.

“It’s unfortunate that a leader such as the president-elect would say things like that, that could motivate people who have hatred to act maybe violently,” Mohamed said. “My fear is that a person who has hatred for Muslims or a hatred for immigrants might decide to do something harmful.”

Noah said that his students in the youth ministry have expressed concern, telling him that they do not feel comfortable attending classes or going to work for fear of retribution or verbal abuse.

“I tell them do not feel this way, that you are as American as everyone else in this country,” Noah said, adding that addressing misconceptions about the faith must be a top priority in the wake of the attack.

Student Ashley Greivenkamp signs a community message board at the Ohio State University student union on Tuesday. (AP Photo/John Minchillo)

Kader is a volunteer with one outreach program called “Ask a Muslim,” regularly meeting with curious members of the community to discuss Islam. He hands out pamphlets with a verse from the Koran reading “whoever kills an innocent human being it shall be as if he has killed all mankind,” and headlined with a simple message: “Islam is not a religion of extremism.”

And yet when Kader takes part in volunteer work, he is on the front lines of discriminatory outbursts. One time a man came up to him and tore apart a flyer about the prophet Muhammad then picked up a Koran and threw it in the trash. In response, Kader said, he offered the man a peaceful blessing. “I feel very honored to represent Islam at a time when Islamophobia has reached a very high level,” Kader said.

Kader said that Artan inquired about taking part in the volunteer effort to spread Islamic teachings by joining the Ask a Muslim program, but that Artan said his family didn’t want him to do it, fearing for Artan’s safety.

As co-presidents of the Muslim Student Association, Ohio State seniors Maliha Masood and Nabeel Alauddin also expressed fears of a possible backlash against the Islamic community.

In a rust-colored headscarf, Masood said that after the presidential election the MSA sent an email to members with safety tips: don’t travel alone, refrain from going out at night, carry pepper spray and beware of your surroundings. After the attack, the student leaders felt compelled to issue another warning to students: “If you need help we’re always here for you.”

Alauddin, 22, said that in recent months Muslim students have reported allegations of hate crimes to the police, including one incident where a woman wearing a hijab was spit on. Alauddin said another time a woman wearing a hijab was riding a bus and saw a man wearing a red hat emblazoned with the “Make America Great Again” slogan say “I can’t wait until we can kill all of them.”

Artan was not a member of the MSA, Alauddin said, and none of the student leaders knew him. Alauddin said the MSA has received an outpouring of support this week.

“I felt heartbroken and I am nervous a little bit about what happens next,” Alauddin said. “It was an attack on our student body, and when it comes to the community, I don’t separate us from the larger student body. But there’s some worry in that it makes things a little bit tense.”

Masood said that the administration has made efforts to be more accommodating, noting that in the past four years the university began serving Halal food for Muslim students. The school also offers an interfaith prayer and reflection room at the student union, she said. The daughter of Pakistani immigrants, Masood, 22, said that she’s never felt excluded because of her faith and that she proudly wears her hijab around campus.

“When you exude an aura of ‘you belong,’ it helps the fact that other people will believe it also,” she said.

Maryam Abidi, 20, said that the attack unearthed uncomfortable memories from her childhood after the Sept. 11, 2001 terrorist attacks, when she didn’t want to go to school because she “was afraid someone would call me a terrorist.” Now as a college student, Abidi said she began to “assimilate” and dress like other young women by wearing dresses that expose the skin on her legs, “to mitigate the Muslim-ness of my outward appearance.”

After the election, Abidi said, students found fliers promoting the “Alt-Right” movement and white supremacy in a campus building. She said that she has felt on edge in public spaces. Abidi said that she feels that the attack on campus will only perpetuate the stereotype of Muslims as radical fanatics.

“I have been very tired of the trope of Muslims having to apologize for everything that happens,” Abidi said. “It’s not on my religion, it’s not on my family, it’s not on my culture.”

Violent acts carried out in the name of Islam, Abidi said, represent corrupted portrayals of the faith: “It’s not the truth,” she said.

Abigail Hauslohner, Susan Svrluga and Matt Zapotosky contributed to this report from Washington.