One person was killed and another seriously injured in a stabbing incident late on Thursday in the Dutch port city of Rotterdam, police said.
Police arrested a suspect who was also injured and taken to hospital for treatment.
Police spokesman Wessel Stolle said officers were investigating the stabbing near the landmark Erasmus Bridge.
Mr Stolle said there was no immediate word on a motive, but “we look into all possible scenarios”.
Dutch daily De Telegraaf, citing witnesses at the scene, reported that a man attacked people at random with two knives while shouting “Allahu Akbar”, the Arabic phrase meaning God is great.
Mr Stolle said police at the scene also had heard that the man shouted the phrase, and that “it’s part of the investigation”.
A sports instructor, Reniel Renato David Litecia, said he hit the attacker with two sticks after seeing him attack somebody and managed to take the knives and throw them away.
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.”
Another police spokesperson, Kristel Arntz, said the assailant is believed to have attacked one person in an underground car park and then a second victim near a busy terrace near one end of the bridge that spans the New Maas river that runs through Rotterdam.
Ms Arntz also said it was too early in the investigation to establish a motive.
“We have arrested a suspect, we are going to question him. We will look at all the witness statements and then we will look at what the possible motive was,” she said.
The identities of the victims and suspect were not immediately clear.
