The Dutch defense minister Ank Bijleveld said the agents worked for the Russian military intelligence GRU agency and that they had used diplomatic passports to enter the country, where they allegedly took pictures of the OPCW's surroundings in The Hague and hacked into the organization's WiFi network from a vehicle parked outside the building.
The charges came as part of a joint crackdown by Britain, The Netherlands, Canada and the United States against a string of hacking attempts by what London called "pariah state" Russian Federation.
Russian Foreign Ministry spokeswoman Maria Zakharova said that these accusations were "big fantasies".
The British and Dutch accusations were unveiled as North Atlantic Treaty Organisation defense ministers gathered in Brussels to present a united front to their Cold War-era foe.
The Dutch and British authorities released CCTV images of the four men arriving at Schipol Airport as well photographs of their passports.
The British ambassador to the Netherlands said the men caught with spy gear outside OPCW were from the very same GRU section (Unit 26165) accused by American investigators of having broken into the Democratic National Committee's email system before the 2016 United States election.
The Russians set up a auto full of electronic equipment in the vehicle park of a hotel next to the Organisation for the Prohibition for Chemical Weapons in The Hague in a bid to hack into its computer system, it said.
British Prime Minister Theresa May has said GRU officers were behind an attempt to kill former Russian double agent Sergei Skripal and his daughter with a nerve agent in the English city of Salisbury in March.
Some of the charges relate to attacks against the World Anti-Doping Agency (WADA) in an effort to undermine the body following the exposure of a Russian state-sponsored athlete doping program.
They had planned to travel on to a laboratory in Spiez, Switzerland used by the OPCW to analyse chemical weapons samples, he said. They were expelled to Russian Federation.
The defendants are all Russian nationals based in Russia and are Aleksei Sergeyevich Morenets, 41, Evgenii Mikhaylovich, Serebriakov, 37, Ivan Sergeyevich Yermakov, 32, Artem Andreyevich Malyshev, 30, Dmitriy Sergeyevich Badin, 27, Oleg Mikhaylovich Sotnikov, 46, and Alexey Valerevich Minin, 46. Reuters was not immediately able to contact them.
Tiger falls to Rahm, finishes 0-4 at Ryder Cup
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The U.S. Justice Department has charged seven Russian military intelligence officers with hacking anti-doping agencies and other organizations.
A British national security report released late on October 3 concludes that the Russian military intelligence agency, or GRU, is "a pernicious cyber-aggressor" that has used a network of hackers to spread discord and confusion across the world.
"The GRUs actions are reckless and indiscriminate: they try to undermine and interfere in elections in other countries", said British Foreign Secretary Jeremy Hunt.
"Clearly there is evidence that very untoward behaviour by the Russians has been at play here, totally outside the norm of civilized behaviour among countries and we're standing with our allies... to call out that illicit behaviour when we see it", Goodale said.
Prosecutors say the Russians also targeted a Pennsylvania-based nuclear energy company and an worldwide organisation that was investigating chemical weapons in Syria and the poisoning of a former GRU officer.
Tensions between the United Kingdom and Russian Federation have been high since the poisoning of retired double agent Sergei Skripal and his daughter earlier this year.
Hunt said the hacking attempt at the OPCW was further proof of Moscow's role in the poisoning. Moscow replied with tit-for-tat expulsions of Westerners.
The night before four Russian spies were caught trying to hack into the world's chemical weapons testing headquarters, they had drunk three cans of Heineken, a bottle of Lowenbrau lager, two bottles of Aldi's pure fruit orange juice and a packet of cold, cooked chicken slices.
Officials said they were from the GRU's Unit 26165, which has also been known as APT 28.
Australia and New Zealand also backed the British findings.
Earlier, Australian Prime Minister Scott Morrison and Foreign Minister Marise Payne issued a joint statement that Australian intelligence agencies agreed that GRU "is responsible for this pattern of malicious cyber activity".