The Netherlands is accusing Russia of carrying out multiple cyberattacks, including one against the Organization for the Prohibition of Chemical Weapons.

Dutch officials said Thursday they caught four members of Russia’s military intelligence service with spy equipment next to the OPCW headquarters in April and expelled them.

The OPCW was investigating the poisoning of a former Russian spy in Britain. Russia has denied any links to the poisoning of Sergei Skripal and Dutch officials said it was not clear if the cyberattack was linked to the investigation.

Russia’s foreign ministry denied the accusations, dismissing them as “fantasies.”

Britain and Australia are also accusing Russia of malicious cyber activity, saying its agents targeted the World Anti-Doping Agency and the 2016 U.S. presidential election.