The intelligence agency said on the Telegram messaging app that its special unit Group 13 attacked the Russian Black Sea Fleet patrol ship Sergey Kotov near the Kerch Strait.

“As a result of a strike by Magura V5 maritime drones, the Russian ship Project 22160 Sergey Kotov sustained damage to the stern, starboard and port sides,” it said. The message added that the ship was worth about US$65 million.

Andriy Yermak, President Volodymyr Zelensky’s chief of staff, said on Telegram today that “The Russian Black Sea Fleet is a symbol of occupation. It cannot be in the Ukrainian Crimea,” in an apparent reference to the attack.

Train traffic was temporarily stopped on the bridge linking the Crimean peninsula to the Russian mainland, according to the Telegram channel of a Russia-installed official in Crimea.

Highway traffic was also suspended for several hours before reopening just before 0700 GMT, according to the Telegram channel of the Russian-installed administration managing the bridge.

Reuters was unable to verify the reports. The Russian defence ministry did not immediately reply to a Reuters request for comment.

Ukrainian military said last month it had destroyed a Russian landing warship near Crimea in an operation with naval drones that breached the vessel’s port side and caused it to sink.