Dutch authorities thwarted an attempted Russian hacking attack on the United Nations chemical weapons watchdog, the Dutch defense minister announced on Thursday.

Four Russian GRU agents were expelled from the country for attempting a cyberattack on the Organization for the Prohibition of Chemical Weapons in The Hague, Ank Bijleveld told a news conference. The Russian ambassador has been summoned for an explanation.

The group had allegedly positioned a car full of electronic equipment in the car park of the Marriott Hotel next to the OPCW building and were trying to hack its computer system. The equipment included a hidden antenna to intercept wireless network communications in the building.

Inside, the OPCW was attempting to identify the substance used in the March poisoning of former Russian double agent Sergei Skripal and his daughter Julia as well as the identity of a substance used in an attack in Douma, Syria.

The group allegedly planned to travel on to a laboratory in Spiez, Switzerland used by the OPCW to analyze chemical weapons samples.

"The Dutch government finds the involvement of these intelligence operatives extremely worrisome," Bijleveld said. "Normally we don't reveal this type of counter-intelligence operation."

He said that a laptop belonging to one of the four was also linked to operations in Brazil, Switzerland and Malaysia. The Malaysia events were allegedly related to the investigation into the 2014 shooting down of flight MH17 over Ukraine.

US charges 7 Russians

The US Justice Department announced after the revelations that it had charged seven Russian military intelligence officers with hacking anti-doping agencies and other organizations.

Prosecutors said Russia targeted the hacking victims because of their public positions on Russia's state-sponsored athlete doping program.

They said the GRU had also targeted a Pennsylvania-based nuclear energy company and the OPCW.

US Defense Secretary Jim Mattis said Russia must be held accountable for its attempts to hack the OPCW.

"Basically, the Russians got caught with their equipment, with people who were doing it and they have to pay the piper, they are going to have to be held to account. How we respond is a political decision by the nations involved," Mattis said after a meeting with his NATO counterparts.

Canada too

Shortly after the Netherlands revealed its claims, Canada said it too had been targeted by Russian cyberattacks. It said it had detected breaches at its center for ethics in sports and at the Montreal-based World Anti-doping Agency.

"The government of Canada assesses with high confidence that the Russian military's intelligence arm, the GRU, was responsible" for these cyberattacks, the Foreign Ministry said in a statement.

NATO warning

The head of the North Atlantic Treaty Organization, Jens Stoltenberg, warned Russia to cease its "reckless" behavior.

He backed the Netherlands and the UK and said Moscow had shown a pattern of attempted election interference and disinformation campaigns.

"NATO will continue to strengthen its defense and deterrence to deal with hybrid threats, including in the cyber domain," he said. NATO defense ministers were meeting on Thursday to discuss new offensive cyber capabilities.

UK, Australian accusations

Read more: UK, Australia blame Russia for series of global cyberattacks

Earlier, British and Australian authorities accused Russia of being behind multiple global hacking attacks, calling it a "pariah state."

British Defense Secretary Gavin Williamson said:  "Where Russia acts in an indiscriminate and reckless way, where they have done in terms of these cyberattacks, we will be exposing them."

Russia responded to those allegations by calling them "big fantasies" and saying the UK had a vivid imagination.

On Wednesday US news outlets reported that Washington was expected to make its offensive cyber warfare capabilities available to NATO, in an attempt to strengthen its defenses against Russian electronic attacks.

aw/ng (AFP, Reuters, AP)