Turkish President Tayyip Erdogan said on Monday that attacks on commercial ships in the Black Sea were unacceptable, issuing a warning to “all related sides” after an unmanned vessel reportedly struck a tanker off Turkiye’s northern coast.

“The war between Russia and Ukraine has clearly begun to threaten navigational safety in the Black Sea. The targeting of vessels in our Exclusive Economic Zone on Friday signals a worrying escalation,” Erdogan told reporters.

“We cannot justify these attacks in any way. We are conveying the necessary warnings to all relevant sides regarding such incidents.”

Turkiye said on Saturday that the Virat, a tanker that forms part of Russia’s so-called shadow fleet, was hit late on Friday by an unmanned vessel some 35 miles off Turkiye’s Black Sea coast.