An overnight Ukrainian drone attack on an oil depot near Russia's Black Sea resort of Sochi sparked a major fire, Russian officials said on Sunday, as the two countries traded strikes and the Ukrainian president announced a prisoner exchange. More than 120 firefighters attempted to extinguish the blaze, which was caused by debris from a downed drone striking a fuel tank, Krasnodar regional Governor Veniamin Kondratyev said on Telegram. 

Videos on social media appeared to show huge pillars of smoke billowing above the oil depot. Russia's civil aviation authority, Rosaviatsia, temporarily stopped flights at Sochi's airport. Farther north, authorities in the Voronezh region reported that four people were wounded in another Ukrainian drone strike.

Russia's Defence Ministry said its air defences shot down 93 Ukrainian drones over Russia and the Black Sea overnight into Sunday. Meanwhile, in southern Ukraine, a Russian missile strike hit a residential area in the city of Mykolaiv, according to the State Emergency Services, wounding seven people.