"Around 2:30 am (0030 GMT) on December 26, tactical aviation of the Air Force attacked with cruise missiles the Novocherkassk large landing ship of the Black Sea Fleet of the Russian Federation in the area of Feodosia," it said in a post on messaging platform Telegram.

Feodosia is home to a major Russian naval base on the occupied Crimean peninsula.

In an earlier message, it said the Novocherkassk had been "destroyed", adding that "people say that it transported Shaheds", referring to Iranian explosive drones used regularly by Russia against Ukraine.

Air force commandant Mykola Olechtchouk posted a video of a fiery explosion at the Russian naval base in Feodosia.

Sergey Aksyonov, the Kremlin-backed head of Crimea, said: "An enemy attack was carried out in the area of Feodosia".

"The port area is cordoned off," he wrote on Telegram.

"As of now, the detonation has stopped and the fire has been localised. All relevant services are on site. Residents of several houses will be evacuated."

Ukraine frequently carries out strikes in Crimea, particularly targeting the Russian military.

In April 2022, it sank the cruiser Moskva, the flagship of the Black Sea fleet.