BERLIN, Germany: An off-duty police officer shot an unidentified man dead Wednesday evening on a train in the city of Flensburg after he attacked, stabbing the officer and another passenger.

The attacker, who has yet to be identified with police claiming they are still unclear of his age and nationality, stabbed the off-duty police officer who was armed and in uniform at the time, along with another bystander who received serious injuries Die Welt reports.

So far, according to the DPA news agency, police have not been able to confirm whether or not the attack had a radical Islamic extremist motive behind it saying they had no evidence so far of ties to extremist groups or ideology.

Police say the motive for the attack still remains unclear but some sources have alleged that the attacker had entered into a heated argument with another passenger and the off-duty police officer had come to them following an announcement over the train loudspeaker asking if there were any police on board the train.

Hospital: Two Islamist Axe Attack Victims In Critical Condition https://t.co/MP9wOHupfX pic.twitter.com/ZV3GHHA3JR — Breitbart London (@BreitbartLondon) July 21, 2016

German Interior Minister and leader of the Christian Social Union Horst Seehofer commented on the incident wishing both victims a speedy recovery and saying, “violence must never be tolerated, whether directed against the population or against police officers.”

The attack echoes similar attacks that have occurred on trains in Germany in recent years including an axe attack on a train in Wurzburg in 2016 committed by an Afghan asylum seeker in which several Chinese tourists were injured.

The 17-year-old, later identified as Riaz Khan Ahmadzai, was revealed to have not only been in contact with the Islamic State terror group but had been ordered to carry out an attack using a car. Ahmadzai declined the proposition because he could not drive, opting to attack a train instead.