Ukraine says its forces have destroyed a Russian missile ship in the Russian-controlled southern region of Crimea.

Ukraine's defense intelligence agency said on Thursday that one of its units sank the Black Sea Fleet's Ivanovets in the waters off the western side of Crimea.

Released footage shows what appear to be Ukrainian sea drones winding their way toward a warship. In the footage, a large hole can be seen on the side of the vessel after an explosion on the water.

Ukraine is believed to be intensifying its offensive in areas around Crimea, as the situation in the eastern part of the country remains stalled. Russia's defense ministry said on Wednesday that its forces intercepted Ukrainian missiles over Crimea and the Black Sea.

Meanwhile, Russia's Investigative Committee said on Thursday that DNA analysis has identified the remains of the people on board the Russian transport plane that crashed in western Russia on January 24. Russia said 65 Ukrainian prisoners of war were aboard the aircraft.

The committee also said the plane was downed by missiles from a Patriot surface-to-air missile system that the United States gave the Ukrainian military.

It released an image of what it claims is a missile fragment with the word "Patriot" on it. It says the fragment was recovered at the crash site.

Observers say Moscow appears to be using the crash of the plane to put pressure on countries that support Ukraine. On Thursday, the Russian lower house of parliament, or Duma, approved a motion that urges the US Congress to abandon its support for Kyiv.