Russian warships escorted merchant vessels as they passed through the North Sea and the English Channel, while the British Royal Navy monitored the group’s movements. The surveillance operation lasted three days.

According to the Royal Navy, the destroyer HMS Duncan, the frigate HMS St Albans and the patrol vessel HMS Severn were deployed to track two Russian warships and two cargo vessels. The UK also involved HMS Mersey and a Merlin helicopter in the operation.

Britain classifies the escorted merchant vessels as part of Russia’s so-called shadow fleet. London has previously taken action against ships it places in this category. On June 14, British authorities seized the tanker Smyrtos in the English Channel, as announced by Keir Starmer, who was serving as UK prime minister at the time.

The Daily Telegraph later reported that British authorities were considering selling more than 100,000 tonnes of oil carried aboard the seized tanker.

On August 12, Russian President Vladimir Putin accused several Western countries of attempting to restrict the movement of civilian vessels operated by Russian economic entities in violation of international maritime law.

Putin described the possible seizure of such vessels and subsequent sale of their property as «piracy and robbery.» He warned that Moscow would be forced to respond with reciprocal measures and said Russia’s response would not necessarily be limited to the areas where actions against Russian vessels take place.