FBI officers
FBI officersReuters

The FBI said on Wednesday that the Somali-born student who carried out Monday’s car-and-knife attack at Ohio State University might have been inspired by the Islamic State (ISIS) group, but would not confirm that the group was directly responsible for the attack as it has claimed.

Law enforcement officials said that it is too soon to say the rampage that hurt 11 people was terrorism, adding they aren't aware of any direct contact between ISIS and the attacker, Ohio State student Abdul Razak Ali Artan.

"We only believe he may have been inspired" by the group, said Angela Byers, the top FBI agent overseeing federal investigations in the southern half of Ohio, according to The Associated Press.

Artan also might have been influenced by Anwar al-Awlaki, a U.S.-born cleric who took a leadership role in the Al-Qaeda terrorist group before being killed in a 2011 U.S. drone strike in Yemen, Byers added.

Al-Awlaki has been cited as inspiration by numerous terror suspects over the years, including the brothers who bombed the Boston Marathon, the Army psychiatrist who killed 13 people at Fort Hood, Texas, and, more recently, the man charged in bombings in New York and New Jersey.

Rep. Adam Schiff of California, the top Democrat on the House Intelligence Committee, said investigators are still going through Artan's electronic devices, but it seems clears he was radicalized online.

He added there doesn't seem to be much time between the onset of Artan's apparent radicalization and the attack, a period known in law enforcement and intelligence circles as "flash to bang."

"This may be one of those cases which was just unpreventable," he said, according to AP, adding that there was no evidence yet to suggest Artan had been publicly communicating radical intentions over a long period of time.

Schiff added that the fact that Artan may have been inspired by a cleric killed five years ago shows the "limits of taking people off the battlefield."

"As long as you have disaffected or alienated young people who are searching for something to belong to, the lure of this radical propaganda will continue to be very dangerous," Schiff said.

The FBI said it was looking to verify whether Artan posted rantings on Facebook hours before the Ohio State attack criticizing U.S. interference in Muslim lands and warning of more Muslims in sleeper cells.

The 18-year-old was fatally shot by a police officer shortly after driving into pedestrians and then slashing others with a knife. A preliminary autopsy released Wednesday showed Artan died from gunshots to the head and chest.

On Tuesday, a self-described ISIS news agency called Artan "a soldier of the Islamic State" who "carried out the operation in response to calls to target citizens of international coalition countries."

The Islamic State group has described other attackers around the world as its "soldiers" without specifically claiming to have organized the acts of violence, noted AP.

"They have been known to take credit for incidents like this when the assailant is deceased and can't refute that," Byers said, adding that the investigation has not found that anyone else was involved in the attack or the planning of it.

If the attack is indeed a jihadist-inspired terrorist attack, it would not be the first such attack in the United States in recent years.

Just a year ago, in December of 2015, Syed Farook and Tashfeen Malik carried out a massacre in San Bernardino, California, killing 14 people and injuring 22 others.

The FBI later said that Farook and Malik were both radicalized "for quite some time". It is believed Farook had contact with people from at least two terrorist organizations overseas, and investigators have also said Malik had pledged allegiance to ISIS in a Facebook posting.

In another incident, Faisal Mohammad, a California college student who stabbed four people late last year was reported to have been carrying an image of the black flag of ISIS as well as a handwritten manifesto with instructions to behead a student and multiple reminders to pray to Allah.