Nine people were taken to hospital and three were in serious condition. The driver was also hurt in the accident and was taken to hospital.
Police said the 26 year-old Romanian was driving a BMW, lost control of the car because of excessive speed and entered the opposite lane and hit 13 waiting at a bus stop.
Italian media claims the driver, Bruno Radosavljevici, is a Romanian citizen born in Turin and currently living in a Roma camp in Rome.
"I tried to avoid a pedestrian, lost control of the wheel and hit those other people,” the driver reportedly said.