Moscow [Russia], December 3 (ANI): President Vladimir Putin has threatened to 'cut off Ukraine from sea,' after Kyiv's underwater drone strike on two tankers of Russia's 'shadow fleet' in the Black Sea last week.

'The most radical way to stop these actions would be to cut Ukraine off from the sea,' Putin said as reported by TASS, Russia's leading news agency.

Putin further termed Ukrainian attacks as 'piracy' and stated that Russia will consider 'retaliatory measures' against 'ships from countries' that are supporting Ukraine's piracy.

'Ukrainian attacks on tankers in the Black Sea are piracy: Attacks on tankers not even in neutral waters, but in the special economic zone of another state, a third state, are piracy,' he said.

'Russia will consider 'retaliatory measures' against ships from countries that support Ukraine's piracy,' he added.

Putin further stated that Russia will expand its strikes on Ukrainian ports and ships entering those ports, TASS reported.

On Friday and Saturday, Ukrainian underwater drones struck two Russian tankers. A security source confirmed that Sea Baby maritime drones were used in a joint operation involving Ukraine's Security Service (SBU) and its navy.

According to the Ukrainian source, both tankers suffered critical damage and were effectively knocked out of operation. 'This will deal a significant blow to the transportation of Russian oil,' the source said.

Russia uses hundreds of tankers - many sailing under different flags of convenience - to ship its oil to customers in defiance of sanctions, as per CNN.

One of the targeted vessels, the Gambian-flagged tanker Virat, was struck for a second time on Saturday after already sustaining damage the previous day, Turkey's Transport Ministry said.

'There is no request from the personnel to abandon the ship,' the Turkish transport ministry said, but a firefighting tugboat had been sent to the scene.

Virat's destination remained unclear. Shipping data indicated it was waiting for orders somewhere in the Black Sea. The tanker was sanctioned by the United States in January -- under a different name at the time -- and later faced sanctions from both the United Kingdom and the European Union.

A second explosion hit another sanctioned tanker on Friday in a nearby part of the Black Sea. The Gambian-flagged Kairos, which transports Russian crude oil, was severely damaged, and all 25 crew members were evacuated. Neither vessel was inside Turkish territorial waters during the attacks. (ANI)