A sea drone shows the silhouette of Olenegorsky Gornyak ship near the port of Novorossiysk, Russia, in this screengrab obtained from social media video [Source: Reuters]

A Russian warship was seriously damaged in an overnight Ukrainian naval drone attack on Russia’s Black Sea navy base at Novorossiysk, the first time the Ukrainian navy has projected its power so far from the country’s shores.

The port, which handles 2% of the world’s oil supply and also exports grain, temporarily halted civilian ship movement before resuming normal operations, according to the Caspian Pipeline Consortium which operates an oil terminal there.

Russia’s Defence Ministry said a Ukrainian attack by two sea drones had been repelled in the waters outside the base and that the drones had been destroyed. It made no mention of any damage in its short statement.

A Ukrainian intelligence source said the Olenegorsky Gornyak, a Russian Navy landing ship with around 100 Russian servicemen on board, had been hit by a sea drone carrying 450 kilograms of TNT.

“As a result of the attack, the Olenegorsky Gornyak received a serious breach and currently cannot conduct its combat missions,” the source told Reuters, adding that the operation had been carried out by Ukraine’s Security Service and the navy. “All the Russian statements about a ‘repelled attack’ are fake.”

Video footage verified by Reuters showed the Olenegorsky Gornyak being towed to shore by a tug, listing heavily to its port side.

Andriy Ryzhenko, a retired Ukrainian Navy captain and naval consultant, estimated the sea drones had travelled 740 km (460 miles) from their likely launch area to Novorossiysk, which would amount to a significant increase in their range.

“It was the first time … the Ukrainian navy projected power so far away,” he said.

A source with knowledge of the port’s operations said a large Russian naval vessel had to be towed ashore because it could not move under its own power after being damaged.

The source, who did not name the vessel, said oil and grain loadings were still taking place at the port, which resumed normal operations hours after the attack.

Ukraine referred to the Olenegorsky Gornyak without directly claiming responsibility for the attack.

“We have open information that it is indeed damaged,” said Natalia Humeniuk, spokesperson for the southern military command said, adding “it is absolutely legal to destroy the potential of the enemy in time of war.”

The Kremlin referred questions to the defence ministry, which did not immediately respond to a request for comment.

The Ukrainian source shared a grainy video that looked like it had been shot from the top of a maritime drone that sails right up to the side of a large vessel before the video abruptly cuts out and turns to pixels.

“Another Russian ship is teetering, undermining the aggressor’s security reputation in the Black Sea waters,” Ukraine’s foreign ministry said on X, previously known as Twitter, adding that one of its compartments had flooded.

Andrei Kravchenko, a Novorossiysk city official, said on the Telegram app that the Olenegorsky Gornyak was one of two ships that had “instantly reacted” to fend off the Ukrainian attack.