Ukrainian underwater drones attacked two tankers belonging to Russia’s so-called shadow fleet in the Black Sea, according to Ukrainian Security Service (SBU) officials.
Ukraine claimed the attack after two ships were hit by explosions on Friday and Saturday.
A Ukrainian security official told CNN that the SeaBaby maritime drone was used in joint operations by the SBU and the navy. There was no immediate comment from Russia.
Officials said both tankers sustained significant damage and were effectively grounded. “This will be a serious blow to Russian oil transportation.”
Russia uses hundreds of tankers, many of them sailing under different flags of convenience, to transport oil to customers in defiance of sanctions.
Turkey’s Transport Ministry said the Gambian-flagged tanker Virat was attacked again on Saturday after first being damaged on Friday.
Turkish maritime authorities said there was light damage above the waterline and no fires. The ship is located about 50 kilometers off the Turkish coast. Ship tracking data showed the ship slowing and circling toward the coast late Friday.
Türkiye’s Transport Ministry said there were “no requests from its staff to abandon the ship,” but firefighting tugboats were called to the scene.
Turkey’s Foreign Ministry expressed concern that the attack “poses a serious risk to navigation, life, property and environmental security in the region.”
Virat’s destination was unknown. Shipping data showed it was waiting for orders in the Black Sea. It was sanctioned by the United States in January when it sailed under a different name, and by the United Kingdom and the European Union later this year.
There was also an explosion on Friday on another ship carrying Russian crude oil near the Black Sea. All 25 crew members of the Gambian-flagged tanker Kairos were evacuated. Neither vessel was in Turkish waters at the time of the collision.
Video showed Turkish tugboats tackling a large fire on board the ship, about 30 miles off the Turkish coast. Türkiye’s Ministry of Transport announced on Saturday that the fire on the open deck of the Kairos had been extinguished.
Kairos has a total length of 275 meters and weighs approximately 80,000 tons. It left an Indian port earlier this month and returned to Russia’s Black Sea port of Novorossiysk following EU sanctions earlier this year.
Earlier this year, multiple unexplained explosions occurred on a ship transporting oil from the Black Sea to Russia.
Both the Virat and Kairos rivers passed through the Bosphorus and entered the Black Sea. Other ships sanctioned for transporting Russian crude oil were also traveling along the same route, according to shipping data on Saturday.
The Caspian Sea Pipeline Consortium said there was also a maritime drone attack early Saturday morning at a berth in Russia’s Novorossiysk port on the Black Sea.
The pipeline transports oil from Kazakhstan through Russia to customers overseas. After the strike, Kazakhstan’s energy ministry said it had “activated a plan to redirect oil exports to alternative routes.”
Novorossiysk has been repeatedly attacked by Ukrainian drones. CNN has reached out to Ukrainian security officials for comment.