Three pro-Russian hackers have been arrested for alleged cyberattacks against Spain and other NATO countries for terrorist purposes, Spanish police said on Saturday.

The suspects were detained for their alleged participation in distributed denial of service (DDoS) cyber attacks against public institutions and strategic sectors, the Civil Guard said.

It did not say if the three suspects, who have not been named, have been charged or detained

The cyberattacks were allegedly carried out against web pages of public and private organizations in the government sectors, critical infrastructures and essential services in countries which support Ukraine in the conflict with Russia, it said.

Police released a video on social media platform X of a raid at the home of one of the suspects in which a Soviet-era hammer and sickle flag was mounted on a wall.

“These computer attacks have been organized by the hacktivist group NoName057(16), (which started) after the invasion of Ukraine by Russia and (which has been) one of the most active,” the Civil Guard said in a statement.

“In their own founding manifesto, this group acknowledges that they ‘will respond proportionately in response to the hostile and openly anti-Russian actions of Western Russophobes’.”

The arrests took place in Manacor on Spain’s Balearic Island of Mallorca, and in Huelva and Seville, in southern Spain, police said.

Police said the investigation was ongoing.

(Reporting by Graham Keeley)