PARIS — The French military on Wednesday arrested two crew members on a tanker suspected of belonging to Russia’s shadow fleet and of having been involved in drone disturbances in Denmark last week, according to the French prosecutor’s office.

French military personal boarded the Boracay, a Benin-flagged tanker that is suspected of being used by Russia to bypass EU sanctions, according to pictures taken by the AFP news agency.

The tanker is also suspected of having served as a launchpad for the drones seen in Denmark last week ahead of an EU leaders’ summit in Copenhagen. The Boracay was positioned more than 50 kilometers outside the Port of Saint-Nazaire on Wednesday after travelling from the Russian Port of Primorsk in the Baltic Sea, according to shipping data checked by POLITICO.

The two crew members, the captain and his deputy, were arrested on charges of refusing to obey a summons and failing to justify the ship’s nationality, according to the prosecutor’s office.

Discussions between EU leaders in Copenhagen Oct. 1 were dominated by Russia drone incursions against EU countries and a proposal by the European Commission to create a “drone wall” on its eastern frontier in response to the sightings.

Speaking after the arrests, Danish Prime Minister Mette Frederiksen said she couldn’t comment on “specific investigations” but noted that countries were “facing lots of problems with the shadow fleet in the Baltic Sea.”

On Wednesday morning, French President Emmanuel Macron said “a very important operation” was ongoing in relation to the Boracay. “There were very important offenses committed by the crew which justify the legal proceedings,” he said on arrival at the summit.

Macron refrained, however, from linking the ship to the drone sightings.

According to the Guardian, the Kremlin said on Wednesday it had no information about a ship suspected of belonging to the Russian shadow fleet off the coast of France.

Gabriel Gavin contributed reporting.