The attacker, who is believed to be from Somalia, pulled out the knife after being asked for his ticket on the number 11 bus in Rimini, Italy.
He attacked the two female drivers with the knife before fleeing.
The man then stabbed three other people in the horrific attack, including a woman and a child, according to the TGCom24 media outlet.
While the two drivers were not seriously injured, the child was stabbed in the throat, local press reported.
The armed attacker managed to get off the bus by ordering the driver to open the door while threatening him with a knife, before escaping on foot.
Once on the road, he also attempted to hijack a car.
But, after running to nearby train tracks, the police managed to capture and arrest the assailant.
The arrest of the man was ordered by the prosecutor Davide Ercolani.
According to TG Comm 24, the attacker was accommodated in a Red Cross establishment with some witnesses describing him as having a “violent and aggressive personality”.
It is believed that investigators did not rule out the possibility that he was under the influence of drugs during the attack.