The Royal Navy has deterred Russian submarines identified in the vicinity of undersea cables and other critical under water infrastructure.
A Russian attack submarine and specialist submarines from Russian’s Main Directorate for Deep-Sea Research (Gugi), were involved in the operation.
The vessels were designed to survey undersea infrastructure during peacetime and to sabotage it in conflict, defence secretary John Healey said today.
The Ministry of Defence said that it would not confirm the nature of the cables in the vicinity of the Russian submarines.
But Healey said that undersea communications cables were essential for digital communications that underpin international trade.
“Subsea fiber optic cables are essential for all digital communications, with over 99% of international data, including voice calls and internet data, travelling through undersea cables. This underpins global banking, trade and communications,” he added.
The incident follows concerns raised by MPs and peers that internet and communications cables linking the UK are vulnerable to sabotage attempts.
Distraction operation
British aircraft and warships identified and tracked a Russian Akula attack submarine entering international waters north of the UK several weeks ago.
The Royal Navy deployed a Type 23 frigate and Merlin helicopters to monitor the attack submarine near British territorial waters.
The submarine was intended as a distraction from operations by Russian undersea naval units from Gugi operating near critical undersea infrastructure elsewhere.
The UK worked with Norway and other allies to monitor the Russian deep sea underwater research vessels.
“Our aircraft flew over 450 hours. Our frigate covered several thousand nautical miles. 500 British personnel were involved in the response,” said Healey.
“To President Putin, I say this: we see you, we see your activity over our cables and pipelines. And you should know that any attempt to damage them will not be tolerated, and will have serious consequences”.
The Gugi units and the Akula class submarine retreated back home having failed to complete their operation in secrecy, the Ministry of Defence said.
Russian spy ship Yantar gathered intelligence
The UK has seen a 30% increase in Russian vessels threatening UK waters over the last two years, according to the Ministry of Defence.
The Russian spy ship Yantar, was tracked by a warship and RAF P8 planes after it tested British defences last year.
The ship was observed in January 2025 “gathering intelligence and mapping the UK’s critical underwater infrastructure”.
In returned to British UK waters in November, when it was tracked by a Royal Navy Frigate and RAF planes.
MPs say UK needs to do more
A cross-party group of MPs and peers warned last year that the UK has “been too timid” in defending the undersea internet cable network from potential attacks by Russia.
The UK is a global hub for internet traffic, and almost entirely reliant on subsea cables to exchange data with other countries.
It has about 62 subsea cables, roughly 50 of which are thought to be active, linking it to rest of the world. They provide resilience if some are deliberately or accidentally damaged. Additional cables run through the Channel Tunnel.
Threats increasing
Healey said that the UK’s undersea network is highly resilient but that threats were increasing.
He said that UK was investing £100 million in P8 submarine hunting aircraft and had launched the Atlantic Bastion programme, which is funding the development of anti-submarine sensing technology.
The UK has signed the Luna House agreement with Norway, to protect critical infrastructure in the North Sea, through a joint fleet of ships.
