British forces boarded a sanctioned oil tanker in the English Channel early on Sunday, the first UK-led operation of its kind targeting Russia’s so-called shadow fleet.
Royal Marine Commandos and officers from the National Crime Agency boarded the Smyrtos in UK territorial waters, according to the government. The six-hour operation was supported by Royal Navy ships, military helicopters and an RAF P-8 maritime patrol aircraft.
The vessel will be moved to an anchorage off England’s south coast while authorities continue their investigation and monitor for environmental or safety risks.
The UK said the action was carried out under domestic and international law, after Prime Minister Keir Starmer approved the boarding of shadow-fleet vessels in March. The government said the ship was targeted as part of efforts to enforce sanctions designed to curb revenue used to fund President Vladimir Putin’s war in Ukraine.
“This operation delivers yet another blow to Russia and reminds those fueling Putin’s war in Ukraine that they cannot hide,” Starmer said.
Dan Jarvis, who was appointed as UK defense secretary on June 11 following the resignation of John Healey, said the interdiction would disrupt a fleet that Russia relies on to move sanctioned oil and finance its war effort against Ukraine.
Sunday’s peration was conducted in coordination with France, and follows UK support for previous US and French actions against shadow-fleet vessels.
The UK has sanctioned almost 600 vessels linked to Russia’s shadow fleet, which it says numbers more than 700 ships and carries about three-quarters of Russia’s sanctioned oil. Britain said ships sanctioned by the UK carried $1.6 billion less Russian oil in the first quarter of 2025 than a year earlier.
The government said Russia’s oil and gas revenues fell 24% year-on-year in 2025, while oil revenues were down 27% from October 2024, reaching their lowest level since the start of the war in 2022.
Many of the vessels are aging tankers operating with opaque ownership and insurance arrangements. More than 70% of shadow tankers are over 15 years old, and there have been more than 50 incidents involving the fleet, according to the UK government.
Photograph: Military helicopters are seen alongside the Smyrtos tanker in Portland, England on June 14, 2026; photo credit: Finnbarr Webster/Getty Images
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