LONDON — British armed forces boarded a Russian shadow fleet oil tanker in the English Channel in the early hours of Sunday, in the first operation of its kind by the UK, officials said.
Royal Marine Commandos and specially trained officers from the National Crime Agency intercepted the vessel Smyrtos during a six-hour operation supported by the Royal Air Force, the Ministry of Defence said. The Cameroon-flagged tanker, previously known as Myrtos, was sanctioned by the UK in 2025 for its involvement in transporting Russian oil.
Prime Minister Keir Starmer said he directed the action as the vessel attempted to pass through the Channel. “This successful operation delivers yet another blow to Russia and reminds those fuelling Putin’s war in Ukraine that we will not let them hide,” Starmer said in a statement.
The Smyrtos is now being held and monitored off the south coast of England, near Weymouth, as investigations continue, the MoD said. The vessel will be provisionally moved to an anchorage while environmental and safety concerns are addressed.
The operation follows a decision by the UK government in March 2026 to authorise its armed forces and law enforcement agencies to intercept and detain sanctioned shadow fleet vessels transiting British waters, including the English Channel. The shadow fleet consists of older tankers used by Russia to export oil in circumvention of Western sanctions imposed over its conflict with Ukraine.
Defence officials have described the shadow fleet as a key mechanism for Russia to generate revenue that supports its military activities. The UK and its allies have sanctioned numerous vessels in the fleet, though many continue to operate by changing names, flags and other identifiers.
The MoD confirmed that the boarding was conducted safely, with involvement from naval assets including a frigate and minehunter. Details of any cargo or the precise legal basis for the detention beyond sanctions remained subject to ongoing investigation.
Ukrainian President Volodymyr Zelenskyy welcomed the interception, according to reports. Russian officials have not yet issued a public response to the specific incident.
The UK has previously supported allied operations against shadow fleet vessels, including assisting French forces in an interception in the Atlantic in early June. Sunday’s action marks the first time UK forces have directly boarded such a tanker in British waters.
Investigations into the Smyrtos and its operations are continuing, the MoD said.
