Türkiye on Tuesday said a tanker reported coming under attack in the Black Sea on its way from Russia to Georgia, days after two other vessels were hit off the Turkish coast.
A Ukrainian security source told AFP their forces had carried out the earlier attacks, with drones targeting vessels that were "covertly transporting Russian oil".
Türkiye's maritime affairs directorate wrote on X that the latest incident was communicated on Tuesday morning by the Midvolga 2, which "reported that it was attacked 80 nautical miles off our coast".
It was "sailing from Russia to Georgia loaded with sunflower oil".
"The ship, which currently has no adverse conditions among its 13 personnel, has no request for assistance," it said.
The vessel was heading towards the port of Sinop in the central area of Türkiye’s Black Sea coast, which stretches some 1,600 kilometers along the southern flank of the sea.
The maritime website VesselFinder lists the Midvolga 2 as an "oil/chemical tanker".
It did not give an updated position for the vessel, whose location was last listed on November 21 when it was said to be travelling from the Turkish port of Samsun to Russia's Rostov-on-Don.
Turkish President Recep Tayyip Erdogan said the drone attacks on Friday were a "worrying escalation".
"We cannot under any circumstances accept these attacks, which threaten the safety of navigation, the environment and lives in our exclusive economic zone," he said on Monday evening.
"The conflict between Russia and Ukraine has clearly reached a stage where it threatens the safety of navigation in the Black Sea."
The two empty oil tankers, the Virat and the Kairos, both reported explosions on Friday but there were no injuries reported.
The Kairos was struck around 1500 GMT en route to the Black Sea port of Novorossiysk, with rescuers evacuating its 25 crew after a fire broke out, Turkish officials said.
At the time, it was about 100 kilometers (60 miles) east of the point where the Bosphorus Strait enters the Black Sea.
The Virat was struck later. At the time, it was about 400 kilometers further east, according to the VesselFinder tracking site, and it reported a second explosion in the early hours of Saturday morning but none of its 20 crew members were hurt.
Türkiye’s transport ministry blamed drones for both attacks on the Virat.
Both tankers -- which were flying a Gambian flag, according to VesselFinder -- are subject to Western sanctions for transporting oil from Russian ports in defiance of an embargo imposed after Russia's 2022 invasion of Ukraine.
