Russian naval forces destroyed three uncrewed Ukraine-launched boats in the northern part of the Black Sea off the Crimean Peninsula, Russia's defense ministry said on Tuesday.
"Anti-sabotage missiles and bombs hit the area where the unmanned boats were detected," the ministry said on the Telegram messaging app.
It added that an anti-mining and an "anti-sabotage" operation was being carried out off Sevastopol port, which is home to Russia's Black Sea Fleet.
It was not immediately clear whether the incident caused any casualties or damage.
Reuters could not independently verify the report. There was no immediate comment from Kyiv.
Ukraine has intensified its attacks on Crimea since midsummer, trying to undermine Russia's efforts in the 20-month-long war. Russia seized and annexed Ukraine's Crimean Peninsula in 2014.
In September, Kyiv said it damaged two naval vessels and struck Sevastopol's port infrastructure in what appeared to be the biggest attack of the war there.
The Kremlin uses Sevastopol and the Black See Fleet to project power into the Middle East and Mediterranean and - during the war in Ukraine - to impose a de facto blockade on Ukraine's seaborne food exports via the Turkish straits.
