Russia's defense ministry said its forces had prevented Ukraine from attacking the Black Sea port of Sevastopol on Sunday, destroying seven aerial and two underwater drones.
"This morning, an attempt by the Kyiv regime to carry out a terrorist attack by seven unmanned aerial vehicles and two unmanned underwater vehicles on objects on the territory of the Crimean Peninsula near the city of Sevastopol was thwarted," the ministry said on the Telegram messaging app.
There were no casualties and no damage, the ministry added.
It said that two aerial drones were shot down over the Black Sea at a great distance from the coastline, while five were intercepted by Russia's electronic warfare forces.
Two unmanned underwater vehicles (UUV), known as underwater drones were discovered in the northern part of the Black Sea, and destroyed by fire, the ministry said.
Earlier, Mikhail Razvozhayev, the Moscow-installed governor of Sevastopol, said on the Telegram messaging app that the attacks were over the harbor of Sevastopol and the city's Balaklava, Khersones districts.
Maritime transport, including passenger ferries, was suspended for several hours early on Sunday, the city's Moscow-backed transport authorities said on their Telegram channel.
Reuters could not independently verify the reports.
No comment from Ukraine
There was no immediate comment from Ukraine on the attack on Sevastopol, a port in the Crimean Peninsula, which Russia annexed from Ukraine in 2014.
Ukraine almost never publicly claims responsibility for attacks inside Russia or on Russian-controlled territory in Ukraine but has been saying in recent months that destroying Russia's military infrastructure helps Kyiv's counteroffensive.