An off-duty police officer and two other passengers on a regional train in Germany have overpowered a man who wounded five people including the officer with a knife, authorities say.
A top law enforcement official said the 31-year-old attacker, born in Iraq, had been investigated for possible Islamic extremism while living in a refugee hostel in 2017 but that the motive for the train attack had not been determined.
Four of the injured were treated in hospital for wounds to their hands or face and head while one victim had been stabbed in the shoulder blade.
None were in a life-threatening condition.
The attacker was also injured and taken to a clinic.
The train had just pulled out of the station at Herzogenrath near the border with the Netherlands and was heading for the western German city of Aachen at 7.42am when the man began attacking fellow passengers "randomly and arbitrarily," state interior minister Herbert Reul said.
He praised the courage of the 60-year-old off-duty officer and passengers who had "prevented worse harm".
He described the attack as "a gruesome crime that was stopped in an enormous act of courage".
Reul said the man had undergone a police check for possible Islamic extremism in 2017 after the refugee hostel where the man had been living reported that he had grown a beard, changed his behaviour and isolated himself from his fellow residents.