The incident occurred around 16:30 (14:30 GMT), when the speeding car hit the pedestrians in the centre of Modena, south-east of Milan.
“We saw the car approaching, it was heading for the curb,” an eyewitness said.
“It suddenly accelerated – it was going at least 100km/h (62mph).”
“We saw people flying,” the witness told Italian media.
Modena’s mayor said it appeared the driver “deliberately drove on to the pavement, hitting several people and crashing into a shop window”.
“He then got out of his car and brandished a knife,” Mezzetti said.
One man who tried to stop him was lightly injured before others joined him to overpower the attacker.
