Ukrainian officials said their forces hit the vessel with missiles, while Russia acknowledged a fire aboard the Moskva but no attack. U.S. and other Western officials could not confirm what caused the blaze.

The loss of the warship named for the Russian capital is a devastating symbolic defeat for Moscow as its troops regroup for a renewed offensive in eastern Ukraine after retreating from much of the north, including the capital.

Russians Say Ship Sank During a Storm

The Russian Defense Ministry said the ship sank in a storm while being towed to a port. Russia earlier said the flames on the ship, which would typically have 500 sailors on board, forced the entire crew to evacuate. It later said the blaze had been contained and that the ship would be towed to port with its missile launchers intact.

The ship had the capacity to carry 16 long-range cruise missiles, and its removal reduces Russia’s firepower in the Black Sea. It’s also a blow to Russian prestige in a war already widely seen as a historic blunder. Now entering its eighth week, Russia’s invasion has stalled because of resistance from Ukrainian fighters bolstered by weapons and other aid sent by Western nations.

During the first days of the war, The Moskva was reportedly the warship that called on Ukrainian soldiers stationed on Snake Island in the Black Sea to surrender in a standoff. In a widely circulated recording, a soldier responded: “Russian warship, go (expletive) yourself.”

The Associated Press could not independently verify the incident, but Ukraine and its supporters consider it an iconic moment of defiance. The country recently unveiled a postage stamp commemorating it.

The news of the flagship’s damage overshadowed Russian claims of advances in the southern port city of Mariupol, where they have been battling the Ukrainians since the early days of the invasion in some of the heaviest fighting of the war — at a horrific cost to civilians.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said Wednesday that 1,026 Ukrainian troops surrendered at a metals factory in the city. But Vadym Denysenko, adviser to Ukraine’s interior minister, rejected the claim, telling Current Time TV that “the battle over the seaport is still ongoing today.”