On Saturday afternoon, the man in the car allegedly first hit several people in central Modena, then got out of the vehicle and attempted to stab a passerby who had tried to stop him.
According to witnesses, he drove onto the sidewalk at high speed and fled after crashing the car into a building facade.
He was driving at 100 kilometers per hour, a witness said, according to Ansa.
The suspect, who is in his 30s, was arrested after being overpowered by several members of the public.
The city's mayor, Massimo Mezzetti, described it as a "tragic event" but emphasized that much is still unclear.
"I am deeply shocked. Regardless of its nature, it is a very serious incident," he said at the scene, Ansa writes.
The two seriously injured people have been flown by air ambulance to a hospital in Bologna, writes the Gazzetta di Modena.
