A Ukrainian Bayraktar drone destroyed two Russian Raptor-class patrol ships in the Black Sea on Monday, Ukraine's military chief said.
"Two Russian Raptor-class boats were destroyed at dawn today near Zmiinyi (Snake) Island," Chief of General Staff Valeriy Zaluzhniy wrote on the Telegram messaging app.
The defence ministry also released grainy black and white ariel footage showing an explosion on a small military vessel.
There was no immediate reaction from Moscow to the claim.
The Russian ship involved, the Moskva, sank in the Black Sea in mid-April following what Moscow said was an explosion on board. Ukraine said it had hit the warship with missiles.