But a Ukrainian intelligence source said the Olenegorsky Gornyak, a Russian Navy landing ship, had sustained a serious breach and could not conduct combat missions following what they said was a joint operation by the Ukrainian Navy and security service.

Separately, 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 it was 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.

Unverified video footage published on social media purported to show damage to it. In one video, it was seen listing heavily to its port side.

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.

Rising Black Sea Tensions

Russian social media users had reported hearing explosions and gunfire near Novorossiysk on Friday morning.

“Tonight, the armed forces of Ukraine attempted to attack the Novorossiysk naval base with two unmanned sea boats,” the Defence Ministry said in its statement.

“In the course of repelling the attack, the unmanned boats were visually detected and destroyed by fire from the standard weapons of the Russian ships guarding the outer waters of the naval base.”

The Caspian Pipeline Consortium, which loads oil onto tankers in Novorossiysk, said its facilities had not been damaged and that oil loadings continued onto tankers, which were already moored.

Loading

The port is one of the biggest in the Black Sea, and a major terminal for the export of oil and oil products. The Caspian Pipeline Consortium is the main exporter of Kazakh crude oil.

Exports of Russian and Kazakh oil from Novorossiysk average 1.8 million barrels a day, or about 2 per cent of global oil supply.

Britain’s military intelligence service said last September that Russia’s Black Sea Fleet had relocated some submarines from the Crimean port of Sevastopol to Novorossiysk, probably because of the increased threat of Ukrainian long-range strikes.

Russia has also reported an uptick in attempted Ukrainian naval drone attacks on its own warships in the Black Sea.

The Russian Defence Ministry said on Friday that its forces had also repelled an attempted Ukrainian attack on Crimea, which it annexed from Ukraine in 2014, using at least 13 plane-like drones. It said there were no casualties or damage.

AP, Reuters

Get a note directly from our foreign correspondents on what’s making headlines around the world. Sign up for the weekly What in the World newsletter here.