Santantonio said others aboard the train stopped the assailant and handed him over to authorities. Santantonio says the suspect wasn't answering questions, including about motive. Police say the attacker knew the woman but wasn't traveling with her. Santantonio said both the woman and the attacker are Italian.
The train, which started its run in Turin, northern Italy, was taken to Bologna station for the investigation. Its passengers were transferred to another train.