Royal Marines board Russian shadow-fleet tanker in first UK-led sanctions interception

The boarding operation

Early on Sunday, 14 June 2026, British Royal Marines and officers from the National Crime Agency (NCA) boarded the tanker Smyrtos in the English Channel, with air support from RAF Chinook helicopters and other aircraft, as well as a frigate and a minesweeper. The operation lasted about six hours and was coordinated with French authorities, according to a UK government statement. Ministry of Defence video shows commandos rappelling from helicopters onto the vessel’s deck and conducting searches. After the boarding, the ship was detained and moved to waters off the southern coast of England, where investigations continue.

The shadow fleet

The Smyrtos, sailing under a Cameroon flag, had departed on 5 June from the Russian port of Ust-Luga near St. Petersburg. The UK government identifies it as part of Russia’s so-called shadow fleet, a network of more than 700 ships used to circumvent international sanctions on Russian oil exports. The fleet is estimated to carry around 75% of sanctioned Russian oil, providing critical revenue to the Kremlin. The boarding is the first UK-led operation of its kind; previously, British forces had only supported French and American interdictions.

Political reactions

Prime Minister Keir Starmer said on social media that the operation was “another blow to Russia” and warned those enabling Vladimir Putin’s war in Ukraine that “we will not let them hide.”

“This successful operation is another blow to Russia, reminding those propping up Putin’s war in Ukraine that we will not let them hide.”

Ukrainian President Volodymyr Zelensky thanked the UK publicly and urged European nations to go beyond immobilisation and confiscate the oil cargoes carried by shadow fleet vessels.

Domestic and legal backdrop

Starmer had authorised British forces in March to board and detain Russian ships suspected of sanctions evasion, according to reports citing a Reuters analysis. The Prime Minister is facing a political leadership challenge and recently lost his defence minister after a disagreement over defence spending. Despite the change in posture, the same number of Russian ships under sanctions continue to pass through British waters as before the authorisation, Reuters found. The operation was conducted in accordance with national and international law, the UK Ministry of Defence stated, calling it “a clear message: you can’t hide anywhere.”