Russian Navy's reconnaissance ship Liman of the Black Sea fleet sails in the Bosphorus, on its way to the Mediterranean Sea, in Istanbul, Turkey, 18 November, 2015. Reuters

A Russian naval spy ship has sunk off Turkey's Black Sea coast after colliding with a vessel carrying livestock, Turkish officials said.

Crew members of the Russian intelligence ship Liman were rescued unharmed after a hole ripped in their vessel's hull after colliding with the Togo-flagged boat Youzarsif H.

The incident, on Thursday (27 April), took place in fog and low visibility about 18 miles (29km) from Kilyos, just north of Istanbul.

Turkish authorities dispatched a tugboat and three vessels to rescue the 78 crew on board, the coastal safety authority said. There were no reported injuries.

A spokesman for Hammami Livestock, who own the Youzarsif H, said they had no information about the cause of the collision, which occurred at 11.45am local time (8.45am GMT).

"It is considered a slight hit, for us," they told Reuters in Lebanon, suggesting the vessel had sustained only minor damage. "We don't know our losses yet, but thank God there is no loss of life – neither from our side nor from the other ship."

The spokesman said the livestock carrier, built in 1977 and with a 2,418-tonne capacity, had been heading to Jordan's Red Sea port of Aqaba from Romania.

It was not known where the Liman was sailing from or its destination. In February, military sources told Russian media that the Liman would be observing Nato's Sea Shield exercise in the Black Sea.

Russia's Black Sea Fleet (BSF) warships frequently pass through the narrow Bosphorus Strait, a 17-mile waterway through Istanbul that allows passage to the Mediterranean.

Relations between Nato member Turkey and Russia have suffered over the civil war in Syria, with Moscow and Ankara supporting different factions. They reached a low point in 2015 when Turkish war planes shot down a Russian jet over the Syrian border.

Turkish Prime Minister Binali Yildirim spoke to his Russian counterpart Dmitry Medvedev by phone over Thursday's incident, describing it as an accident and expressing his sadness, the state-run Anadolu news agency said.

Cem Devrim Yaylali, an Istanbul-based Turkish naval expert and editor of the Bosphorus Naval News website, said the Liman had previously been to the Syrian coast.

"A collision is not something that happens very frequently," he told AFP, adding that the incident was an embarrassment for the Russian authorities and the vessel would have likely been carrying sensitive surveillance equipment.

"I imagine there will be a salvage effort to raise the ship before anyone else sees it," he said. "If the ship cannot be salvaged then Russia surely will try to take away the sensitive equipment from on board by divers."