Ukraine's Special Forces said on Monday that Admiral Viktor Sokolov, the commander of Russia's Black Sea Fleet, had been killed in a Ukrainian attack last week on the fleet headquarters in the Crimean port of Sevastopol.
The Russian Defence Ministry did not immediately respond when asked by Reuters to confirm or deny that Sokolov had been killed in the attack on Crimea, which Russia seized and annexed in 2014.
The Ukrainian military said Friday's attack had targeted a meeting of the Russian Navy's leadership in the city of Sevastopol.
"After the strike on the headquarters of the Russian Black Sea Fleet, 34 officers died, including the commander of the Russian Black Sea Fleet. Another 105 occupiers were wounded. The headquarters building cannot be restored," the special forces said on the Telegram messaging app.
It was not immediately clear how Ukraine's Special Forces counted the dead and wounded in the attack.
Facts are few and far between
Each side has at times exaggerated enemy losses since Russia's full-scale invasion of Ukraine 19 months ago and each says little about its own losses.
Russian-installed officials confirmed the Ukrainian attack on Friday, saying that at least one missile struck the fleet headquarters.
Kyiv has stepped up attacks in the Black Sea and Crimea as Ukrainian forces press on with a nearly four-month-old counteroffensive to take back Russian-occupied territory.