Ukrainian long-range drone strikes hit eight Russian shadow fleet tankers in the Sea of Azov, Ukraine's top drone warfare commander, Robert Brovdi, better known by his callsign "Madyar," said on July 7.Claiming that the overnight aerial naval battle reached "industrial-scale results," Brovdi reported that the Ukrainian drones also hit a dry cargo ship and a ferry, alongside a convoy of eight fuel tankers. He claimed that the fuel tankers were "badly damaged and on fire.""The shadow fleet is leaving the area," Brovdi said in his Telegram post. "The battle for fuel for Crimea in the Sea of Azov continues."The Kyiv Independent could not independently verify Brovdi's claim. Moscow had not commented at the publication time.The reported Ukrainian drone strikes on a convoy of Russian tankers come as Ukraine ramps up its long-range attacks across the Russian-occupied territories and inside Russia in recent weeks, inflicting a domestic fuel supply crisis on Russia.As part of the gradual efforts to grind down Russia's war machine from afar, Ukraine has targeted the Russian shadow fleet to intensify "pressure on sanctions-busting shippers and insurers at a time when Russian oil exports are already under strain," according to the London-based defense and security think-tank Royal United Services Institute (RUSI). Russia relies on a vast shadow fleet of aging tankers operating under opaque ownership structures and flags of convenience to export oil and petroleum products despite Western sanctions.Ukraine has argued that Russia's shadow fleet vessels may no longer qualify as ordinary civilian shipping under international law, according to a June 26 letter sent by Deputy Prime Minister Oleksii Kuleba to the International Maritime Organization (IMO) and first reported by Lloyd's List.Brovdi claimed that "all tankers" hit in the Ukrainian July 7 overnight strike had been identified. He said they are all subject to international sanctions, have a deadweight of 7,000 metric tons each with a length of 140 meters, and were built between 2006 and 2012.The tankers Brovdi claims Ukraine identified include Venera-3, Sanar-1, Sanar-17, Climene, Teti, Aleksey Savrasov, and Penelope."Sanctions from the skies by the Freedom-Loving Ukrainian Birds of the Unmanned Systems Forces are in effect," Brovdi said.