COLUMBUS, Ohio - An Ohio State student drove a car into a crowd outside a classroom building Monday morning, then got out and slashed at people with a butcher knife, sending 11 people to the hospital in what authorities said was a planned assault.

University public safety officials identified the student as Abdul Razak Ali Artan, who neighbors said belonged to a large Somali family living in Columbus. Authorities said they did not yet know what motivated the attack but could not rule out the possibility of terrorism.

Police responded swiftly to the chaotic scene on campus Monday, and within a minute, a university police officer shot and killed Artan. But it was hours before people understood the details of what had happened on the flagship state campus, as terrified witnesses described a crash, gunfire, stabbings and screaming students sprinting to find a hiding place.

It was yet another sign that universities, once thought of as peaceful havens, are vulnerable to sudden, violent attacks.

The violence prompted a shelter-in-place order at the country's third-largest campus by population, just miles from the Ohio Statehouse.

Police said they believe Artan was 20 years old, and in an interview with the Lantern student newspaper in August he said that he was a junior in logistics management who had transferred from Columbus State Community College.

Columbus State said that Artan was enrolled there from 2014 until last summer, graduating with an associate of arts degree last spring before taking a noncredit class during the summer. Artan had no records of behavioral or disciplinary issues while enrolled there, the school said.

In the interview with the Lantern, Artan described his Muslim prayers and said that Ohio State was so big that he didn't even know where to pray.

"I wanted to pray in the open, but I was kind of scared with everything going in the media," he said. "I'm a Muslim, it's not what the media portrays me to be. If people look at me, a Muslim praying, I don't know what they're going to think, what's going to happen. ... I was kind of scared right now. But I just did it. I relied on God. I went over to the corner and just prayed."

Louann Carnahan lived next door to Artan on the west side of Columbus in a community with many Somali families. She said Artan lived in an apartment with about eight other people, describing him as a pleasant young man who had told her he went to the mosque daily.

Jack Ouham, owner of the Home Town Market near Artan's home, said he lived with several brothers and sisters and his mother in a three-bedroom apartment for the last year. He said the family is Somali but had lived in Pakistan prior to coming to Columbus. He described him as "a really nice guy, really quiet, very friendly. No craziness. A very normal, respectful guy."

Video cameras recorded Artan driving onto the campus and heading to the scene of the attack, showing that he was alone in the car, Craig Stone, chief of the Ohio State University police, said at a news conference. Stone said police do not yet know a possible motive or if anybody else was involved.

Earlier Monday, Stone had said it was too soon to know whether this was a terrorist plot but that it was clear that "this was done on purpose." The Islamic State and al-Qaeda have encouraged followers to carry out knife attacks, and the Islamic State also has urged its supporters to use cars as weapons. In July, a man the militant group called a "soldier" killed dozens with a truck attack in France.

Rep. Adam Schiff (D., Calif.), ranking member on the House intelligence committee, said he was briefed on the attack and said in a statement it "bears all the hallmarks of a terror attack carried out by someone who may have been self-radicalized."

"Here in the United States, our most immediate threat still comes from lone attackers that are not only capable of unleashing great harm, but are also extremely difficult, and in some cases, virtually impossible to identify or interdict," Schiff said.

The choice of weapons in Columbus was consistent with attack instructions recently released by the Islamic State, according to Rita Katz, executive director of the SITE Intelligence Group, which tracks online communications of extremists.

This month, the extremist group released a video about knife attacks after its magazine wrote about using cars for attacks, Katz said.

U.S. intelligence agencies have found no indications that the suspected university attacker was in contact with the Islamic State, a senior counterterrorism official said.

Two law enforcement officials said investigators were looking into reports that Artan had posted frustrations to social media shortly before the attack.

Muslim and Somali leaders in Ohio on Monday night called the attack "horrific," "sickening" and not representative of Islam or Somali culture.

"Today we all came here to condemn this tragic incident," Horshed Noah, a Somali American imam at one of Columbus' largest mosques, told reporters at a news conference organized by the Council on American-Islamic Relations' local chapter.

That Artan was stopped before attacking more people was likely because an Ohio State campus police officer happened to be in the area due to an earlier report of a gas leak. That officer, Alan Horujko, saw the violence and, within a minute, fatally shot Artan, officials said.

The attack sent 11 people to area hospitals Monday, one in critical condition, officials said. The injured included at least one faculty member as well as undergraduate students, graduate students and a university staff member.

Classes were canceled for the rest of the day Monday.