One person is dead and another is gravely wounded after a man screaming 'Allahu Akbar' and carrying two knives went on a stabbing spree late Thursday in the Dutch port city of Rotterdam.

Police have arrested the suspect and spokesman Wessel Stolle said an investigation is ongoing, per AP News. A motive has not been established but officers will "look into all possible scenarios," he said, adding that the fact the suspect was shouting Allahu Akbar is "part of the investigation."

Witnesses said that the suspect began attacking people at random while shouting the Arab phrase meaning God is great, commonly used by Muslims.

A bystander, sports instructor Reniël Renato David Litecia said he was able to hit the attacker with two sticks and wrestle the knives from him before discharging them. He said he initially thought it was a fight, "but when I started running in that direction I saw that it wasn’t a fight. It was a man with two long knives who was stabbing another young guy and when I started shouting he turned around and started approaching everyone who was around him."

The identities of the victims and the suspect have not been disclosed. The suspect is being held at a local hospital to be treated for his injuries.

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