A train heading for Paris has been evacuated after a man locked himself in a toilet.
Rotterdam police said the train and several platforms at Rotterdam Central station have been cleared and negotiators were in contact with the man.
High-speed train operator Thalys said: “Security forces have situation under control. No risk for our passengers.”
The incident comes less than a month after passengers subdued a gunman on board a Thalys train in northern France as it was travelling from Amsterdam to Paris.
NOS state television pictures showed heavily-armed police with protective shields and equipment scanning the train carriages and searching inside.
Last week European rail operators met government officials to discuss whether to beef up train security in the European Union.
The consensus from those talks was that no disproportionate and costly security action should be taken that would hinder high-speed international rail traffic in the European Union.
This means it is unlikely that metal detectors would be installed in European stations and that passenger information would not be systematically collected.