Dutch security services say they expelled four Russians over a cyber attack plot targeting the global chemical weapons watchdog.
The operation by Russia's GRU military intelligence allegedly targeted the Organisation for the Prohibition of Chemical Weapons in The Hague in April.
The OPCW has been probing the chemical attack on a Russian ex-spy in the UK.
The allegations are part of an organised push-back against alleged Russian cyber attacks around the world.
A joint statement from British Prime Minister Theresa May and her Dutch counterpart Mark Rutte said the alleged plot demonstrated "the GRU's disregard for global values and rules that keep us all safe".