Ukrainian drones have attacked a dozen tankers from Russia's "shadow fleet" over the past two days that were delivering fuel to Crimea, Kyiv's military said on Tuesday, as it intensifies efforts to isolate the Russian-occupied peninsula.
Ukraine's drone forces said they had struck eight vessels subject to sanctions in the Sea of Azov, each with a deadweight of around 7,000 tonnes. Two more tankers were hit later in the day, they added.
The strikes followed attacks on two other shadow-fleet vessels in the same area a day earlier, according to the drone forces. The Sea of Azov is a key supply route for Russian forces in Crimea and other occupied parts of southern Ukraine.
Ukraine has stepped up attacks on logistics and energy infrastructure in Crimea in recent weeks, contributing to fuel shortages and prompting authorities to declare a state of emergency in the peninsula, a critical hub for Russia's war effort.
Russia annexed Crimea in 2014, eight years before launching its full-scale invasion of Ukraine. Moscow has not publicly commented on this week's attacks, which also included strikes on electrical substations, radar systems and missile installations.
In an interview with Reuters last month, Kyiv's top drone commander, Robert Brovdi, pledged to effectively cut off Crimea from Russia through a campaign of systematic strikes.
Ukraine's drone forces posted drone footage - which Reuters could not independently verify - showing vessels being attacked and erupting into flames.
"Striking the enemy's naval logistics complicates the supply of fuel and ammunition necessary to support the activities of Russian troops, primarily in the temporarily occupied territory of Crimea," the forces said in a statement.
Only two of the seven identified vessels initially reported as struck on Tuesday were under international sanctions, according to a Reuters review.
Ukraine has long urged its allies to crack down on vessels that circumvent sanctions to transport Russian oil to international markets.
Kyiv has previously used sea drones to attack tankers carrying Russian oil in the Black Sea as part of a broader effort to reduce Moscow's energy revenues.
There have also been a series of unexplained blasts on tankers that had previously called at Russian ports. Ukraine has neither confirmed nor denied involvement, although maritime security sources have said they suspect Kyiv was behind the incidents.
(Reporting by Anna Pruchnicka and Dan Peleschuk; Additional reporting by Tom Balmforth and Gleb Stolyarov; Writing by Dan Peleschuk; Editing by Mark Potter and Kevin Liffey)