A Russian patrol ship has been damaged after being attacked by sea drones in the Black Sea, according to Ukrainian intelligence. The Sergei Kotov was allegedly hit in the early hours of Tuesday morning. Ukraine's military intelligence service said the Black Sea fleet ship suffered damage to the stern as well as right and left sides. The Kremlin is yet to comment. Some Russian pro-war bloggers have confirmed the attack. Ukrainian intelligence official Andrii Yusov told Ukrainian broadcaster RFERL sailors on board had been killed and injured. The Sergei Kotov is one of four patrol ships completed for the Russian Navy's Project 22160. It had previously been attacked by Ukraine in September last year. According to Ukraine, the vessel played a part in the attack on Snake Island on the first day of the full-scale invasion of Ukraine in February 2022, along with the Moskva cruiser. The Moskva was sunk by Ukraine in 2022. Russia illegally annexed the Crimean peninsula from Ukraine almost 10 years ago. In recent months Ukraine has repeatedly hit Russia's Black Sea fleet stationed on the peninsula. Ukraine said the cost of the sunken Sergei Kotov ship was $65m (£51.2m), adding that it was hit near the Kerch Strait, which separates Crimea from Russia. A video posted on social media appears to show the moment when the ship was hit. BBC Verify has looked at the video, released by Ukraine's Main Intelligence Directorate, which is said to be of the attack. The vessel has similar structural features to a patrol ship of the same class as the Sergei Kotov. However, no number is visible on its side, so the footage does not make clear if it is the same ship. No other versions of the video have appeared on reverse image searches, suggesting the video was released recently. At least 13 Russian naval ships have been destroyed or damaged since the start of the conflict, according to the International Institute for Strategic Studies think tank. Last month, another Russian amphibious ship, the Caesar Kunikov, was sunk in a drone attack just south of the town of Yalta. At the time, Ukraine's intelligence directorate released video of what it said were Magura V5 sea drones striking the Caesar Kunikov. — BBC