A student drove a car into a crowd of pedestrians at Ohio State University and then jumped out and stabbed several people with a butcher knife, injuring 11, before a police officer shot and killed the attacker.

Abdul Razak Ali Artan was shot and killed within minutes by a police officer after ploughing into the group, said Monica Moll, director of public safety for Ohio State University.

“It frankly took a piece out of everybody here at our beautiful Ohio State University that this could have happened here,” Ohio Governor John Kasich said at a news conference.

A US government official confirmed the assailant was from Somalia, 18 years old and a lawful permanent resident of the United States.

A second government source said investigators had reason to believe the attacker at the campus in Columbus was a Somali refugee. Columbus, the state capital, has a large Somali population.

US Congressman Adam Schiff, a California Democrat and the ranking member of the House Permanent Select Committee on Intelligence, said intelligence agencies were assisting in the investigation.

“It bears the all of the hallmarks of a terror attack carried out by someone who may have been self-radicalised,” Schiff said in a statement.

Another US official said US agencies are investigating the Columbus attacker’s background and motivations, but cannot clearly say yet whether he had any ties to suspected militant cells or groups.

With nearly 60,000 students, the Columbus campus is the state’s flagship public university.

The university campus remained open, although classes were canceled for the day.

EARLIER

A man ploughed his car into a group of pedestrians at Ohio State University and then got out and began stabbing people with a butcher knife before he was shot to death by an officer, campus police say.

On Monday morning 10  people were hurt, one critically, and Columbus Police Chief Kim Jacobs said police were looking into whether it was a terrorist attack. The FBI and other agencies joined the investigation.

The details emerged after a morning of confusion and conflicting reports that began with the university issuing a series of tweets warning students that there was an “active shooter” on campus near the engineering building and that they should “run, hide, fight”.

Numerous police vehicles and ambulances converged on the 60,000-student campus, and authorities blocked off roads.

Buckeye Alert: Active Shooter on campus. Run Hide Fight. Watts Hall. 19th and College.

— OSU Emergency Mngmnt (@OSU_EMFP) November 28, 2016

“Run, hide, fight” is standard protocol for active shooter situations. It means: Run, evacuate if possible; Hide, get silently out of view; or Fight, as a last resort, take action to disrupt or incapacitate the shooter if your life is in imminent danger.

The university followed up with another tweet: “Continue to shelter in place in north campus area. Follow directions of Police on scene.”

Buckeye Alert: Continue to shelter in place in north campus area. Follow directions of Police on scene.

— OSU Emergency Mngmnt (@OSU_EMFP) November 28, 2016

The campus was secured 90 minutes later and the “shelter in place” lifted, but classes have been cancelled for the rest of the day. The university said in instructions to students there would be a visible law enforcement presence for the rest of the day.

With nearly 60,000 students at its main Columbus campus, Ohio State is one of the nation’s largest universities.

NBC quoted students as saying they heard gunfire, but also said it was unclear if any of the injured were shot, with reports that the attacker may have wielded a large knife.

Others said a car ploughed into a crowd of people, with a police office being among them.

Other students tweeted and texted different versions of what happened.

https://twitter.com/DylHarrington/status/803280858933264392

Ohio Governor John Kasich tweeted his support for the university.

Ohio's thoughts and prayers go out to the Ohio State community. Be safe, listen to first responders. https://t.co/5qtfH3Fb6d

— John Kasich (@JohnKasich) November 28, 2016

– with AAP