Russian flagship sinks off Ukraine in setback for Putin's forces

April 14 (UPI) -- The flagship of Russia's Black Sea fleet sank Thursday, the Russian Defense Ministry said one day after Ukraine claimed to have severely damaged the Moskva with a missile.

Russian officials said the ship sank while being towed during a storm, according to The New York Times. Moscow said it had to evacuate the vessel, which can carry hundreds of sailors and is a vital part of the country's ability to make war at sea.

Russian officials acknowledged that the ship was damaged, but did not mention any Ukrainian attack.

Officials in the Odesa region on the Black Sea said that two Ukrainian missiles struck the vessel. If confirmed, it would be the first time that Ukraine has hit a Russian ship at sea.

The Moskva is perhaps best known for firing on Ukraine's Snake Island against defiant troops in February at the start of the war.

Russian officials said the ship was hit by an explosion and sustained "serious" damage. They noted that the blast sparked a fire and caused ammunition onboard to detonate. Russia's military said the cause of the explosion was unknown.

Ukrainian official Maksym Marchenko, however, said Ukraine's forces hit the Moskva with a rocket.

"Neptune missiles guarding the Black Sea caused very serious damage to the Russian ship," Marchenko said, according to The Guardian.

The Moskva had previously been docked at the Crimean port of Sevastopol on April 7, according to Maxar satellite images.

Alessio Patalano, a professor of war and strategy at King's College in London, said that the strike on the Moskva would be a substantial tactical and psychological loss for the Russian military.

"Ships operate away from public attention and their activities are rarely the subject of news," Patalano told CNN. "But they are large floating pieces of national territory, and when you lose one, a flagship no less, the political and symbolic message -- in addition to the military loss -- stands out precisely because of it."

The Moskva was the warship that fired on 13 Ukrainian border guards on Snake Island shortly after the invasion on Feb. 24. The ship fired on the guards after they refused, using colorful language, to surrender to Russian forces. It was initially reported that the guards were killed, but they were detained and later released in a prisoner swap.

Russian forces in recent days have been withdrawing from northern parts of Ukraine, including the capital Kyiv, to focus more on fighting in eastern regions such as Donetsk and Luhansk, collectively known as the Donbas -- where pro-Moscow separatists have been at odds with the Ukrainian government for nearly a decade.

Russian President Vladimir Putin said earlier this week that the goal of the Russian military is to "save people" in Ukraine, particularly separatist-heavy eastern Ukraine. Putin's publicly stated claims since the war began have been almost universally refuted.

Meanwhile, Russian Security Council Deputy Chairman Dmitry Medvedev -- who was president of Russia between 2008 and 2012 -- cautioned on Thursday that Scandinavian countries Finland and Sweden would instantly become enemies in Moscow if they decide to join NATO. Both countries recently have indicated that they might become part of the defensive alliance.

Both Finland and Sweden said this week that they are closer to joining NATO as a result of Russia's bloody war in Ukraine. NATO was formed in 1949 as a deterrent against the type of military aggression from Nazi Germany that caused World War II.

The alliance presently has 30 member states -- including Russian neighbors Estonia, Latvia, Lithuania and Poland. The leaders of all four countries traveled to Kyiv on Wednesday to meet with Ukrainian President Volodymyr Zelensky in a show of support against the Russian invasion.

"If Sweden and Finland join NATO, the length of the alliance's land borders with the Russian Federation will more than double. Naturally, these borders will have to be strengthened," Medvedev said according to CNBC.

Medvedev added that Sweden and Finland joining NATO would mean that Russia would have to "seriously strengthen the grouping of land forces and air defense, deploy significant naval forces in the waters of the Gulf of Finland."

"In this case, it will no longer be possible to talk about any nuclear-free status of the Baltic -- the balance must be restored," he said.