According to the Il Resto del Carlino newspaper, the man -- a 28-year-old local with links to the far-right Northern League party -- fired his first shots around north of the city and then drove around the city centre, apparently targeting immigrants.
Local authorities said that after the suspect's arrest it was safe for residents to go outside, after issuing an alert around midday warning locals to stay inside until the "dangerous situation" had subsided.
All of the victims have been hospitalized, although only one appears to have been seriously injured, with a shot hitting her in the abdomen.
"The wounded persons are of foreign nationality," police said in a statement.
The paper claims that the shooting began at 11.00am and continued for about two hours until the man was arrested, having abandoning his car near the town's war memorial.
After leaving the car, the man mounted the monument and performed a fascist 'Roman' salute.
The police have released a picture of the shaven-headed man, draped in an Italian flag, as he was taken away.
According to La Repubblica the suspect had put himself forward as a candidate for Italy's Northern League in the 2017 municipal elections, and was pictured in a party manifesto next to the party's mayoral candidate Luigi Baldassarri. He failed to win a seat.
According to the newspaper, the man has admitted to both carry out the shootings and to performing a 'Roman salute', another name for the fascist gesture.
Local media have linked the attack to the murder of an 18-year-girl whose dismembered body was found in two suitcases last Wednesday. Police are holding a Nigerian man custody over the killing.
The local municipality raised an alert at around 12pm, warning residents to stay inside until the "dangerous situation" had subsided. Following the suspect's arrest a few hours later, the mayor said it was safe to go outside.