At least one person was killed while a Russian navy vessel suffered extensive damages in a Ukrainian attack on the Crimean port of Feodosia Tuesday.
Kyiv said it had destroyed an important Russian warship, a claim denied by Moscow.
The Russian Defense Ministry was cited by the Interfax news agency as saying that Ukraine had used air-launched missiles to attack Feodosia and that the "Novocherkassk" large landing ship had been damaged in the raid.
The "Novocherkassk," which was built in Poland and entered service in the late 1980s, is designed for amphibious landings and can carry various types of armored vehicles, including tanks.
Footage posted on several Russian news outlets on the Telegram messaging app, purportedly from the port, showed powerful explosions detonating and fires burning.
Sergei Aksyonov, the Russian-installed governor of Crimea, said on the Telegram messaging app that one person had been killed, two injured and six people evacuated from their homes.
Although a Ukrainian counteroffensive has made little in the way of battlefield gains and the Russian military has regained the initiative in several places, Ukraine has been able to launch a series of attacks on Crimea, the headquarters of Russia's Black Sea Fleet, inflicting serious damage.
The Ukrainian air force said its pilots had attacked Feodosia at about 2:30 a.m. (12:30 a.m. GMT) with cruise missiles, destroying the "Novocherkassk."
"And the fleet in Russia is getting smaller and smaller! Thanks to the Air Force pilots and everyone involved for the filigree work!" the commander of Ukraine's air force, Mykola Oleshchuk, said on Telegram.
A statement from the Russian-installed administration of Crimea said that trains were not running from Feodosia and advised people to use an alternative nearby station.
Feodosia, which has a population of around 69,000 people, lies on the southern coast of the Crimean Peninsula.
Russia annexed Crimea from Ukraine in 2014 in a move Kyiv and the West condemned as an illegal seizure.
