UK reveals Russian intellgence gathering and submarine activity

Satellite imagery released by the UK MoD showing Russia's Olenya Guba naval base, including what is likely the Delta IV Stretch submarine Podmoskovye (insert bottom right) and intelligence gathering vessel Yantar (insert above). (UK MoD/Crown Copyright)

The UK Ministry of Defence (MoD) said in a 9 April 2026 press release that Royal Navy (RN) assets including Type 23 Frigate HMS St Albans , and a Royal Air Force (RAF) Boeing Poseidon MRA1 (P-8A) maritime patrol aircraft (MPA) had identified a Russian attack submarine entering international waters in the High North in February or March 2026, and tracked its activity.

The MoD said that UK forces established that the submarine was deployed as a distraction. It added that they worked with allies, including Norway, to monitor other Russian undersea naval units. These were from Russia's Main Directorate of Deep Sea Research (Glavnoye Upravlenie Glubokovodnikh Issledovanii: GUGI) conducting what the MoD called “nefarious activity over critical undersea infrastructure [CUI] elsewhere.”

Other UK assets named by the UK MoD were the large fleet tanker RFA Tidespring , and Merlin helicopters used “to track the attack submarine as it operated near British territorial waters.” Both UK aircraft and ships deployed sonobuoys to track the Russian vessels, added the MoD.

Among the Russian units identified by the UK MoD were an Akula-class attack submarine, and two specially modified GUGI submarines. The MoD published satellite imagery of GUGI's Olenya Guba naval base, dated only as 2026, on the Barents sea.