Local authorities in Crimea said Ukraine targeted the port city of Sevastopol with a drone attack on Tuesday.
It was unclear if any damage was done to the city or to Moscow’s Black Sea fleet, which is headquartered there.
“There is an attack with drones,” the Russian-installed governor of the Sevastopol region, Mikhail Razvozhaev, said in a post on the Telegram messaging app. “Our air defense forces are working right now.” He said that two drones had been shot down and that no civilian infrastructure had been damaged.
Mr. Razvozhaev said the drones appeared to be on a course to attack a power plant in the Balaklava district, just east of the city. He said the Russian Navy had repulsed a second group of three drones at sea. None of his statements could be independently verified.
It was the latest in a series of significant attempted strikes in Crimea, which Russia seized illegally in 2014 and uses as base of operations for its invasion into Ukraine. Russia holds Ukraine responsible for the strikes, but Ukrainian officials maintain a policy of official ambiguity about attacks far from the battlefield.
After Russian officials accused Ukrainian forces of a drone attack on the Black Sea Fleet in October, the Kremlin temporarily suspended its participation in a grain deal that provides a safe Black Sea corridor for the grain shipments. Russia has since rejoined the agreement, which was brokered by Turkey and the United Nations.
Although the October strike was far from the route taken by grain ships, Russian officials said they had rejoined the deal after receiving assurances from Ukraine that it would not use the grain corridor to attack Russian vessels.
In the first months of the war, two Ukrainian-made Neptune cruise missiles slammed into the hull of the Moskva, the pride of Russia’s Black Sea fleet. The strike, in April, set off a series of explosions that eventually caused the cruiser to sink, killing an unknown number of sailors.
A senior Ukrainian official acknowledged that the country’s forces had carried out a successful attack in August on the Saki Air Base on Crimea’s western coast. Satellite photos taken after a series of explosions there appeared to show at least eight wrecked warplanes.
More recently, in October, a truck bomb, apparently deployed by Ukrainian saboteurs, severely damaged the main bridge linking Russia to Crimea.