An overnight Ukrainian drone attack on an oil depot near Russia's Black Sea resort of Sochi sparked a major fire, Russian officials said Sunday, as the two countries traded strikes and the Ukrainian president announced a prisoner exchange.

Ukrainian drone attacks sparked a massive fire at an oil depot in a rare attack on the Black Sea resort of Sochi.

More than 120 firefighters were trying to extinguish a blaze at an oil depot in the Russian city of Sochi that was sparked by a Ukrainian drone attack, regional Governor Veniamin Kondratyev said early on Sunday on the Telegram messaging app.