Ten people were injured Monday morning when an attacker drove into a group of pedestrians on the Ohio State University campus, got out of his vehicle and attacked people with a butcher knife.

The attacker was shot and killed, Ohio State spokesman Ben Johnson said.

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

The patients were split among OSU Wexner Medical Center, OhioHealth Grant Medical Center and OhioHealth Riverside Methodist Hospital.

The university had warned students in a series of tweets earlier that there was an active shooter on campus and that they should run, hide or fight.

One tweet said: "Buckeye Alert: Active Shooter on campus. Run Hide Fight. Watts Hall. 19th and College." Watts Hall is a materials science and engineering building.