The flagship of the Russian Black Sea Fleet has been badly damaged after a munitions explosion on board.
"As a result of a fire on the guided missile cruiser Moskva, ammunition detonated," the Interfax news agency said on Thursday, citing the Russian Ministry of Defense.
The entire crew was brought to safety, the cause of the fire is still being investigated.
The 11,500 ton ship normally has a crew of around 500 people on board.
The Ukrainian military says it hit the Russian warship Moskva with a Neptun missile.
The missile cruiser, the flagship of the Russian Black Sea Fleet, was severely damaged, the military command for southern Ukraine said on Facebook.
In the meantime, the Ukrainian presidential adviser Oleksiy Arestovych had claimed that the "Moskva" had sunk.
“Where is the “Moskva”?
'She drowned,'" wrote Arestovych on Twitter.
The governor of the region around the port city of Odessa, Maxim Marchenko, previously said in an online post that the ship had been hit by two Ukrainian Neptun cruise missiles.
According to the Russian Defense Ministry, the fire on the missile cruiser Moskva has been contained.
The warship will now be towed back to the port, the crew has been accommodated on other ships.
The most important weapons of the "Moskva" were not damaged, and the ship is not in danger of sinking.
According to conflicting reports, the missile cruiser was hit either off the Serpent Island, which Russia had conquered, or in the Bay of Sevastopol on the annexed Crimean Peninsula.
Most recently, satellite images from the US provider Maxar showed the "Moskva" in the port of Sevastopol.
Latvian Defense Minister and Deputy Prime Minister Artis Pabriks compared the possible loss of the Moskva to the loss of the German battleship Bismarck in World War II.
It is no wonder that Russia is ashamed to inform its public "about the successful strike against the flagship and Russia's imperial thinking," Pabriks wrote.
According to Kiev, the "Moskva" was involved in one of the most important engagements at the beginning of the war, when Ukrainian border guards on Snake Island, a small promontory in the Black Sea, were attacked by the ship.
19 Ukrainian marines were taken prisoner by the Russians in the attack.
According to the Ukrainian parliament, they were released at the end of March as part of a prisoner exchange with Russia.
According to Russian news agencies, the "Moskva", which entered service with the Black Sea Fleet in 1983, is equipped, among other things, with 16 anti-ship cruise missiles of the "Vulkan" type, which have a range of at least 700 kilometers.
In addition, there are other weapon systems, including anti-submarine weapons.
It was built in the Ukrainian city of Mykolayiv during Soviet times.
In 2015, the warship with its 510-strong crew was deployed in the eastern Mediterranean to protect the Russian Hmeimim airbase in Syria, according to TASS.
Escape corridors are to be opened
Meanwhile, the Ukrainian government has announced the reopening of escape corridors from contested areas in the east and south of the country.
"Nine humanitarian corridors are planned for today," Deputy Prime Minister Iryna Vereshchuk told Telegram on Thursday.
The day before, the evacuations had been suspended for security reasons, according to Ukrainian sources.
The Russian troops violated "international law" and the situation was too dangerous, Vereshchuk said on Wednesday, referring to buses blocked by Russian forces and violations of ceasefires shelling by the occupying forces will cease," she explained.
In anticipation of a major Russian attack in the east, the Ukrainian authorities have been calling on the population of the Donbass region for days to move west to safety.
Dozens of refugees were killed in a rocket attack on a train station in the city of Kramatorsk last week.
Moscow and Kyiv blamed each other.