This is the second Ukrainian operation against a Russian vessel in the Black Sea in a month.
Kiyv claims to have sunk a Russian landing ship during its latest drone attack off the coast of Crimea.
Ukrainian military intelligence released images of naval drones approaching the large landing ship Caesar Kounikov.
According to Kiyv, the ship can carry 87 crew members and has been active in conflicts in Syria, Georgia and Ukraine.
In a video posted on social networks, a plume of smoke rises from a ship believed to be in the Black Sea.
Several Russian media outlets are reporting a search and rescue operation involving helicopters.
The Ukrainian army assures that the attack was carried out with Magura V5. This is the same naval drone used to strike the Russian warship Ivanovets on February 1.
According to the Ukrainian company SpetsTechnoExport, the Magura V5 measures 5.5 meters in length and 1.5 meters in width. Its cruising speed is 40.7 kilometers per hour and it can reach a maximum speed of 77.8 kilometers per hour. The operational range of the naval drone would be approximately 833 kilometers. The payload of the Magura V5 would be 320 kg of explosives.