UK Defence Secretary John Healey stated that British forces tracked a Russian Akula-class attack submarine and two Gugi spy submarines in the North Atlantic north of the UK for a month. The submarines loitered over critical undersea cables before retreating.

Healey confirmed deployment of a Royal Navy warship and RAF P-8 Poseidon aircraft to monitor the vessels around the clock. The operation involved 500 British personnel and more than 50 sorties by RAF crews, with support from Norway and other allies.

The Akula submarine returned home after tracking. The two Gugi submarines, from Russia's Main Directorate of Deep-Sea Research, left UK waters and headed north.

Healey said the submarines operated within the UK's exclusive economic zone, up to 200 nautical miles offshore, but outside territorial waters. He noted prior Gugi activity, including the Yantar spy ship north of Scotland last November, warned off by a Royal Navy submarine.

The Defence Secretary addressed Russian President Vladimir Putin directly, stating that attempts to damage cables or pipelines would face serious consequences. He described Putin as the primary threat to UK security.

Healey explained the Akula submarine likely served as a decoy while Gugi vessels targeted infrastructure. No damage occurred, and the operation exposed the activity to deter further actions.

The Ministry of Defence states Gugi vessels survey underwater infrastructure in peacetime and can damage it in conflict. Concerns have grown over risks to cables and pipelines amid tensions since Russia's Ukraine invasion.