Abdul Razak Ali Artan, Ohio State University attacker, possibly inspired by ISIS, Anwar al-Awlaki

The Ohio State University student who attacked pedestrians on campus with a car and knife may have been inspired by the late al Qaeda cleric Anwar al-Awlaki and the Islamic State, but authorities said it is too soon to definitively call the attack terrorism.

FBI officials said Wednesday the bureau had no prior knowledge of or contact with Abdul Razak Ali Artan, who injured 11 people in Monday’s attack.

The Somali-born student plowed a car into a group of pedestrians on campus, then began stabbing others with a butcher knife Monday morning. A campus police officer fatally shot Artan after he ignored orders to drop the knife.

Investigators have interviewed dozens of family members, neighbors and coworkers who knew Artan and were reviewing his electronic devices in an attempt to learn more about his motivation for the attack and determine the degree to which it may have been premeditated. Artan was a Somali refugee who came to the United States after he and his family had spent several years in Pakistan.

Officials are investigating the authenticity of a post made on Artan’s Facebook page the day of the attack that was critical of the treatment of Muslims. FBI Special Agent in Charge Angela Byers noted that even if the post had been brought to agents’ attention, they would have had a limited amount of time to investigate as it was made the morning of the attack.

“It appears Artan may have at least been inspired by Anwar al-Awlaki and the Islamic State of the Levant,” Ms. Byers said, adding that investigators are not aware of the involvement of anyone else in the attack.

The U.S.-born al-Awlaki was killed by a U.S. drone strike in 2011, having been identified by U.S. intelligence as “chief of external operations” for al Qaeda’s Yemen branch and a web-savvy propagandist for Islamists.

The Islamic State’s media arm claimed Tuesday that Artan was “a soldier” with the terrorist group. Ms. Byers said Wednesday that the group often claims allegiance of individuals after they are dead and cannot refute or verify the claim.

Columbus Police Deputy Chief Michael Woods said investigators have determined that Artan bought a knife at a local Wal-Mart store the morning of the attack, but declined to say whether it was the same knife he used to stab several people.

Citing anonymous sources, NBC News reported that Artan also was believed to have driven to Washington, D.C., the week before the attack and to have bought a different knife at a Home Depot in the nation’s capital.

Investigators asked for help in learning more about Artan’s movements on the day of the attack. Surveillance video shows him driving a car onto campus that morning, but officials are looking to piece together additional stops he may have made in between purchasing the knife Monday morning and driving to school.

“We want to fill in any time not accounted for,” Ms. Byers said.