A Russian naval ship has been damaged in a Ukrainian naval drone attack in the Black Sea, Ukrainian sources say.

The assault is reported to have happened near the Russian port of Novorossiysk, which is a major hub for Russian exports.

Russia’s defence ministry said it had repelled a Ukrainian attack with two sea drones on its naval base there.

But one Ukrainian source told Reuters the Olenegorsky Gornyak was hit and “cannot conduct its combat missions”.

The landing ship is designed to carry equipment and personnel for beach landings.

Russia made no mention of any damage in its report of the incident.

A video sent to the BBC by a source with Ukraine’s security service appears to show the drone approaching a ship thought to be the Olenegorsky Gornyak.

The footage shows a vessel travelling right up to the side of a ship before the feed cuts out.

Ukraine has not officially claimed responsibility for the attack.

The Novorossiysk port temporarily suspended any movement of ships following the assault, according to the Caspian Pipeline Consortium, which loads oil on to tankers at the port.

Sea drones are small, unmanned vessels which operate on or below the water’s surface.

Research by BBC Verify suggests Ukraine has carried out at least 10 attacks with sea drones- targeting military ships and Russia’s naval base in Sevastopol, as well as Novorossiysk harbour in a previous attack.

This is based on announcements by Russian and Ukrainian authorities, and local media reports. Ukrainian defence sources have told CNN that sea drones had also been used in an attack on the Kerch Bridge to Crimea in July.