CHICAGO, United States (AFP) — Eight people were injured when an attacker apparently drove into a crowd at Ohio State University on Monday, triggering an hours-long lockdown before authorities declared the campus secure.

Law enforcement shot and killed one suspect, according to local television station WBNS, which reported that police led two people out in handcuffs from a garage they had surrounded on the university’s main campus in Columbus.

A witness suggested that a suspect was driving a red SUV. The incident was called an active shooter situation, but it was unclear whether any of the victims had suffered firearm injuries. 

Some reports suggested the attacker or attackers used a knife.

“Shelter in Place lifted. Scene is now secure. ALL classes are canceled on Columbus campus for the remainder of the day,” the OSU emergency management services tweeted as it declared the incident over.

Television footage showed students leaving school buildings as Rebecca Diehm, spokeswoman for the Columbus fire department, said eight people had been transported to hospital. 

One was in critical condition, and the rest were stable, she said. 

OSU Wexner Medical Center tweeted that it was treating four victims, none with life-threatening injuries.

– ‘Everybody was running’ –

Earlier the university’s emergency management service had urged students and staff to shelter in place amid reports of an active shooter, as SWAT teams fanned out across the facility.

“Buckeye Alert: Active Shooter on campus. Run Hide Fight. Watts Hall. 19th and College,” the service said in a tweet. A second tweet moments later told the public to “Continue to shelter in place. Avoid area of College.”

Details were murky as the situation unfolded. One student told MSNBC she was walking along a road on campus when a car plowed into a group of people, including a police officer.

Another student, Joseph Noll, said he heard a fire alarm, but no shooting — and also said a car had driven into the crowd.

“I was right there, and there was no one shot,” he told WBNS. “Someone DID run over a crowd of people with their car. I can tell you that for sure.”

“I just heard some screams, and I saw people running,” he said. “And everyone just fled the scene immediately.”

Student Cydney Ireland told ABC she was walking out of class when she also heard screams.

“And then after that — which this is kind of strange — there was a whistle almost like a referee whistle. I wondered if a sports team was practicing. That’s kind of an unusual thing to hear in the academic area,” she said.

“Probably five seconds after that, there were three gunshots.”

“Everybody was running in any direction they possibly could, students were running out of the classroom building,” she said from her hiding spot in a locked bathroom.

Ohio State is one of the largest universities in the United States, with roughly 60,000 students on the main campus in Columbus, which sprawls across more than 1,900 acres (770 hectares).