DUTCH security officials say they have kicked out four Russians from the Netherlands over a cyber attack plot.
Russia's military intelligence allegedly targeted the global chemical weapons watchdog OPCW.
What is the OPCW?
OPCW stands for the Organisation for the Prevention of Chemical Weapons.
The OPCW has been probing the chemical attack on Russian ex-spy Sergei Skripal in the UK.
The allegations are part of a united effort to respond against alleged Russian cyber attacks worldwide.
The Netherlands has summoned the Russian ambassador for an explanation.
Why did Russia's GRU hack the organisation?
The OPCW was investigating the Skripal case as well as an alleged chemical attack on Syria in Douma near Damascus at the time of the hacking.
Four spies tried to hack the Wi-Fi of the Organisation for Chemical Weapons in the Netherlands in April - after a remote attack failed.
Dutch officials said the Russian agents - named as Aleksei Morenets, Evgenii Serebriakov, Oleg Sotnikov and Aleksey Minin - were then booted out of the country after being caught.
Two of them were planning on going on to Switzerland - where the OPCW has labs.
The attacks included repeated hacks on the Ministry of Defence's Porton Down lab, the UK police, and other organisations during a targeted campaign.
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What has the UK said about the incident?
PM Theresa May ordered the exposure of the hacking saying the mission “demonstrates the GRU’s disregard for the global values and rules that keep us all safe”.
Foreign Secretary Jeremy Hunt vowed that international allies were considering what “further sanctions” can be slapped on Russia.
He added on the OPCW hack: “Why would you do that if you weren’t the guilty party?”
The UK's ambassador to the Netherlands, Peter Wilson, said: "With its aggressive cyber campaigns, we see the GRU trying to clean up Russia's own mess - be it the doping uncovered by Wada [global sport anti-doping agency] or the nerve agent identified by the OPCW."
Nato allies said they "stood in solidarity with the decision to call out Russia on its blatant attempts to undermine international law and institutions".