The Ukrainian military said it hit two large Russian landing ships in attacks on the annexed Crimean peninsula early on Sunday, as well as a communications centre and other infrastructure used by the Russian navy in the Black Sea.
The statement did not say how it hit the targets, but a Moscow-installed official in the region reported a major Ukrainian air attack and said air defences had shot down more than 10 missiles over the Crimean port of Sevastopol.
"The defence forces of Ukraine successfully hit the Azov and Yamal large landing ships, a communications centre and also several infrastructure facilities of the Russian Black Sea Fleet in temporarily occupied Crimea," Ukraine's military said.
Mikhail Razvozhayev, the Russian-installed governor of Sevastopol, said on the Telegram messaging app that a 65-year-old man was killed when three homes were hit by shrapnel.
He also said earlier on Sunday that transport infrastructure including passenger boats and buses were partially damaged, with windows broken on five boats. Three passenger buses, 13 school buses and one trolley bus were among vehicles damaged, he added.
The extent of any damage could not be immediately verified.