A Russian tanker has been damaged in a Ukrainian drone attack in the Kerch Strait, briefly halting traffic on the strategic bridge linking Crimea to Russia, Russian maritime officials have said. 

Ukraine’s Interfax agency, citing an unnamed Ukrainian security service source, also said Ukraine’s navy was behind the attack with drones in its territorial waters.

Reuters could not immediately verify the reports. 

Vasyl Malyuk, head of Ukraine’s SBU security service, did not directly say that Ukraine had attacked the vessel, but he commented that any incident with Russian ships or the Crimea bridge was “an absolutely logical and efficient step towards the enemy”.

“Moreover, such special operations are conducted in the territorial waters of Ukraine and are completely legal,” Mr Malyuk said on the Telegram messaging app.

The number of attacks in the Black Sea has increased from both sides since Moscow exited a deal last month that had allowed Ukrainian grain exports via the shipping hub during the conflict between the two countries.

The Russian tanker SIG was hit around 11:20pm local time on Friday south of the Kerch Strait,  Russia’s Federal Agency for Sea and Inland Water Transport said.

The SIG suffered a hole at the waterline in the area of the engine room “presumably as a result of an attack by a marine drone”, the agency said on Telegram.

“The ship is afloat.”

An oil boom had been placed around the vessel and preparations were under way to patch the damage, it said.

The Marine Traffic vessel-tracking website showed the SIG stationary and attended by tugs just south of the strait.