‘We see your activity’: Russian submarines targeted UK undersea cables, pipelines in month-long operation, claims defence secretary

Britain claimed on Thursday (Apr 9) that a Russian submarine operation targeting undersea cables and pipelines north of the UK was deterred in a weeks-long military operation in the North Atlantic along with Norway. Calling it “malign activity” near critical undersea infrastructure, Defence Secretary John Healey said in a briefing that the British response involved a frigate, aircraft and hundreds of personnel. One Russian attack submarine and two spy submarines were operating in a mission that lasted more than a month, after which the vessels withdrew since their mission was exposed, Healey claimed.

"We see your activity": Britain’s warning to Russia over submarine mission

Healey issued a direct warning to Moscow, saying: “We see your activity over our cables and our pipelines and you should know that any attempt to damage them will not be tolerated and will have serious consequences.”

He said Russian President Vladimir Putin “would want us to be distracted by the Middle East”, referring to the Iran-US-Israel war. Healey stressed that Russia remains the primary threat to the UK and its allies, adding: “We will not take our eyes off Putin.”

What the Russian vessels were allegedly doing in UK waters

Healey described the Russian operation as a deliberate, covert mission targeting undersea infrastructure. He said the three submarines conducted the covert operation in waters in and around the UK’s exclusive economic zone, not just the open Atlantic. The Russian deployment had a tactical structure, according to Healey.

An Akula-class nuclear attack submarine acted as “a likely decoy to distract”. Two deep-sea research GUGI submarines carried out the main task, lingering over “critical infrastructure” such as cables and pipelines.

How the UK responded to Russian submarine activity

UK forces “tracked every mile” of the submarines’ movements, and a warship and aircraft ensured they were “monitored 24/7”, Healey said. He said the deterrence effect came from exposing the secrecy of the mission. “Our armed forces left them in no doubt that they were being monitored, that their movements were not covert… and that their attempted secret operation had been exposed,” he said.

Loss of cover appears to have forced Russian submarines to leave

According to Healey, the Russian submarines “have now left UK waters and headed back north”, marking what he called the failure of Putin’s covert operation.

He underlined that no damage was detected to the cables and pipelines, with checks ongoing alongside allies.

He said such seabed infrastructure is a “prime target” because it carries energy supplies and 99 per cent of international data traffic, making these incursions strategically serious even without visible damage.

Overall, the deterrence worked not through direct confrontation, but by persistent tracking, attribution and public exposure, stripping the operation of secrecy and compelling the Russian vessels to withdraw, according to Haley.

Russia’s shadow fleet

The UK is also taking a tougher stance on Russia’s so-called “shadow fleet”, which are ships allegedly used to bypass sanctions on oil exports tied to the war in Ukraine.

“We are ready to take action,” said Healey, including potentially seizing such vessels.