British officials are warning of potential Russian retaliation following the Royal Marines' seizure of the oil tanker Smyrtos, which was intercepted carrying $40 million worth of Russian crude oil roughly 40 kilometres south of the Isle of Wight. The vessel was detained on orders from Prime Minister Keir Starmer after authorities determined it was falsely registered under a Cameroonian flag, rendering it legally stateless; its Indian captain has since been charged with breaching UK sanctions. The UK Chamber of Shipping says owners are exercising heightened vigilance, and tensions were further underscored when a Russian frigate fired warning shots near a British yacht in the English Channel days later — an incident that, while not confirmed as direct retaliation, reflects deepening friction between London and Moscow over the UK's efforts to disrupt Russia's shadow fleet of roughly 600 tankers that fund its war in Ukraine.