Russian navy shipyard targeted by missile strikes in Sevastopol
A Russian submarine and warship were damaged in the pre-dawn barrage on the Sevastopol shipyard - potentially the largest strike against Russian naval targets of the war.
Ukraine used British cruise missiles in a significant attack against the headquarters of Russia's Black Sea Fleet in occupied Crimea, Sky News understands.
A Ukrainian and a Western source said that British Storm Shadow cruise missiles were deployed.
Images on social media captured explosions and flames ripping through the shipyard against a night sky in the very early hours of Wednesday morning.
Russia said 10 cruise missiles were fired against the facility, with seven being shot down by air defences. It said an attack by three unmanned boats was also thwarted.
Ukraine confirmed it struck Russian naval targets and port infrastructure in the city of Sevastopol, which was annexed by Russia in 2014, but has not officially said how.
However, Lieutenant General Mykola Oleschuk, the head of the Ukrainian Air Force, posted an image on his Telegram channel of the burning shipyard, with the caption: "And while the occupiers are 'storming' and they are still recovering from the night cotton [Ukrainian slang for explosions] in Sevastopol, thank you to the pilots of the Air Force of the Armed Forces of Ukraine for their excellent combat work!"
The UK gave Storm Shadow missiles to Ukraine's armed forces earlier in the year. They are able to be fired by Ukrainian aircraft, with a range of more than 150 miles.
France has also supplied the Ukrainian military with cruise missiles.
"It was Storm Shadow," one of the sources said.
Britain's Ministry of Defence has not yet made a comment.
Admiral Sir Ben Key, the head of the Royal Navy, was asked about the Sevastopol attack during a speech at an arms fair in London.
He did not talk about any specifics and was not asked about the potential involvement of missiles given by the UK, but he said: "[The Ukrainians] are demonstrating what can be done through innovative thought processes and a willingness to take risk.
"As we have seen in a number of various areas, some really significant adaptations of tactics, techniques and capabilities in order to try and generate a capability advantage over the Russians and I really applaud that."
This is the first known successful attack against a Russian submarine of the war.
Mikhail Razvozhayev, the Moscow-installed governor of Sevastopol, the largest city in Crimea and a major Black Sea port, said on Telegram that at least 24 people were injured.
"All emergency services are working on the site, there is no danger to civilian objects in the city," Mr Razvozhayev wrote.
The strategic shipyard on the peninsula, which Russia annexed from Ukraine in 2014, builds and repairs ships and submarines of the Russian Black Sea Fleet.
The fleet has launched numerous drone and missile attacks on Ukraine.
Mr Razvozhayev posted a night-time photo of flames engulfing what seemed to be port infrastructure. Russian Telegram channels posted videos and more photos of massive flames at a facility alongside the water.
Rob Lee, a military analyst, posted a series of videos and images on social media purporting to show the strike.
He cited another social media channel as identifying the submarine that had allegedly been at the dry dock as being the Black Sea Fleet's Rostov-on-don Project 636.3 diesel submarine.
The landing ship was identified as the Russian Baltic Fleet's Minsk Project 775 Ropucha-class large landing ship.
Source: Sky News