Russian ships appear to be acting with more caution in the Black Sea after a series of Ukraine marine drone attacks decimated Putin’s navy in the region.In a recent “interesting incident,” a group of Russian vessels appeared to approach the Bosporus Strait before unexpectedly turning around instead of crossing to Russian-held Crimea, according to a Ukraine Navy spokesman.

The Black Sea Fleet has been targeted by Ukraine throughout the war as it seeks to reverse Russian President Vladimir Putin’s 2014 annexation of Crimea. The region serves as Moscow’s central logistics hub for its forces in southern Ukraine, and Ukrainian President Volodymyr Zelensky has pledged to recapture the peninsula.

“Recently, an interesting incident occurred when they sent two ship units to escort their vessels from the Bosporus. That doesn’t happen often, only about once a month. But at some point, they just turned around and headed back,” Dmytro Pletenchuk, the Ukraine Navy spokesman, said on Ukrainian television, according to Ukrainian news agency Unian.

While it was unclear what the motive for the U-turn was, Pletenchuk speculated that the ships’ commanders may have been tipped off about a “threat,” noting that it represented a “positive tendency” for Ukraine.

“These vessels were forced to move along the Turkish border, in effect hiding out in Turkish territorial waters. Thus not taking the shortest route, which they would normally take, but instead fleeing to their hiding spots,” the spokesperson added.