Royal Marine Commandos, supported by the RAF and joined by National Crime Agency (NCA) officers, boarded a Russian shadow fleet oil tanker in the English Channel early Sunday morning. The six-hour operation, the first of its kind by UK armed forces, saw the vessel Smyrtos intercepted and searched.

The vessel will be held and monitored off the south coast of England as investigations continue, according to the Ministry of Defence (MoD). The NCA confirmed that 25 crew members were on board the tanker. This action represents a significant move by the UK to disrupt Russia's oil trade, which has been targeted by international sanctions.

During the operation, armed personnel were observed fast-roping from a helicopter onto the vessel, with further footage showing searches of cabins and NCA officers inspecting paperwork. The Ministry of Defence stated that Russia has been utilizing a "shadow fleet" of over 700 tankers to circumvent international sanctions on its oil exports, carrying approximately 75% of the country's sanctioned oil and providing a "critical lifeline" to the Kremlin.

The Prime Minister had announced in March that British armed forces would be empowered to board sanctioned vessels passing through UK waters. The UK has so far sanctioned over 500 such vessels. These sanctions prohibit sanctioned ships from entering UK ports and prevent British entities from providing financial, insurance, or brokerage services related to the supply or delivery of Russian oil.

According to tracking data from MarineTraffic, the Smyrtos sails under a Cameroon flag and was anchored off the coast of Weymouth. Its journey began on June 5 from Russia's Ust-Luga port, a significant oil terminal near St. Petersburg. The vessel was previously sanctioned in July 2025 and had its name changed from Myrtos to Smyrto.

Sir Keir Starmer commented on the operation, stating that it "delivers yet another blow to Russia and reminds those fuelling Putin's war in Ukraine that we will not let them hide." Moscow has not yet responded, but has previously characterized similar interceptions as illegal and akin to international piracy.

The "shadow fleet" is a key strategy employed by Russia to continue its oil exports despite Western sanctions aimed at curbing its revenue streams. The MoD's description highlights the substantial role these vessels play in maintaining Russia's oil trade.

The Ministry of Defence confirmed that Royal Marine Commandos collaborated with specially trained law enforcement officers from the National Crime Agency for this complex operation, underscoring the inter-agency cooperation involved in enforcing sanctions.