However, a spokeswoman for national train operator Trenitalia told AFP that there were only "minor injuries," with the majority being bruises.
"It was a low-speed collision," he added, adding that an inquiry into what transpired was ongoing.
Firefighters' photos showed the two trains colliding head-on, although the front of the regional train was still intact.
Matteo Salvini, the transport minister and deputy prime minister, said he was monitoring the situation and confirmed the injuries were mild.
He stated that he was looking for quick answers about what transpired and probable blame.
On august 31, five railway workers were killed when a train collided with them during nocturnal maintenance on the Milan-Turin line.
The latest fatal rail disaster in italy occurred in 2020, when a train derailed before morning near Lodi, south of Milan, killing two rail workers and injuring 31 passengers.
In addition, three ladies were killed and around 100 passengers were injured when a crowded train derailed in Milan in january 2018, an event blamed on poor track maintenance.