British forces boarded a Cameroon-flagged sanctioned oil tanker of the Russian "shadow fleet" in the English Channel in the early hours of 14 June, the first time the UK has led such an operation itself, UK Prime Minister Keir Starmer announced. The six-hour boarding of the Smyrtos marks the latest European move against the aging tankers Moscow uses to keep its oil flowing past Western sanctions.

A six-hour operation in the English Channel

Royal Marines and specially trained officers from Britain's National Crime Agency boarded the Smyrtos, the UK Ministry of Defence said. Backing the operation were military aircraft, an RAF P-8 surveillance plane, and two Royal Navy ships, HMS Sutherland and HMS Ledbury. The vessel is now anchored off England's southern coast, near the seaside town of Weymouth, and will be watched for any environmental or safety risks as investigations continue.

"In the early hours of this morning, I directed our Armed Forces to intercept a shadow fleet oil tanker attempting to pass through the English Channel," Starmer wrote on X. "This successful operation delivers yet another blow to Russia and reminds those fueling Putin's war in Ukraine that we will not let them hide."

UK Defense Secretary Dan Jarvis, who took the post last week, said the operation required skill, professionalism, and courage. Moscow leans on the shadow fleet to bankroll its war against Ukraine, he said, and the interception deals a blow to Putin's illegal war.

The ship and its trail

The Smyrtos is a crude oil tanker built in 2009, sailing under the flag of the West African nation of Cameroon, tracking data show. It left the Russian Baltic port of Ust-Luga on 1 June and sat motionless near the Isle of Portland, off England's south coast, after the boarding. The vessel had previously hauled crude from Russia's Pacific port of Kozmino to China.

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Part of a wider European push

The operation was run in tight cooperation with France, extending the help Britain has lately given its allies. French President Emmanuel Macron said on 1 June that his navy had boarded a sanctioned Russian tanker in the Atlantic with British help. In February, Belgian forces, backed by French helicopters, seized a tanker in the North Sea.

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Britain said it has blacklisted almost 600 shadow-fleet ships, the vessels that move three-quarters of Moscow's sanctioned crude and feed a war chest funding the missiles and drones that hit Ukrainian civilians. Russia's oil-and-gas revenues fell 24% from a year earlier in 2025, the UK Ministry of Defence said, crediting the sanctions.

A single boarding leaves hundreds of tankers still sailing — 184 sanctioned vessels passed through British waters in the weeks after the UK's March threat — but a first British-led interception raises the risk and cost for a fleet whose entire value to Moscow rests on moving oil quietly and without interruption.