A British professor who was among the 11 people injured on Monday at Ohio State University says he will reserve judgment about the perpetrator even after the Islamic State of Iraq and the Levant (Isil) claimed responsibility for the attack

William Clark, an Oxford graduate and professor emeritus at Ohio State, evacuated the engineering building after a fire alarm went off due to an unrelated gas leak, and was waiting to return inside when he heard a "tremendous crash" and was subsequently struck by a car.

Abdul Razak Ali Artan, an 18-year-old student, had mounted the curb, struck a cement planter and then driven into Dr Clark and one other victim.

Dr Clark said the car, "clipped the back of my right leg and flipped me up in the air". As he lay on the ground Artan emerged with a butcher's knife and began to stab students who had been walking between classes.