Ukraine has used the British-supplied Storm Shadow missiles in Russia for the first time, a Western official has reportedly confirmed.
The unnamed official revealed 12 missiles were launched into the Kursk region on Wednesday, Bloomberg reported.
Unconfirmed images and footage posted to X/Twitter have shown residents in the village of Marino, Kursk, stumbling upon fragments of the missile.
One image shows a resident holding a thick chunk of broken metal in their hand, while another reveals a written indentation reading: 'Storm Shadow'.
Britain's Storm Shadow missiles are capable of dodging air defences - making them a nightmare attack weapon for their enemy.
The £800,000 rockets use GPS technology to precisely blast targets, and can travel through the air at 600mph.
British sources have described the historical development as 'important'.
Storm Shadow missiles have already been used by Ukraine inside its own territory for some time, but Kyiv now appears to have been granted permission to use the weapons to strike within Russia.
Images being shared on social media show what appear to be fragments of a British Storm Shadow missile in Marino, Kursk
One image shows a written indentation on a chunk of metal reading: 'Storm Shadow'
The £800,000 rockets use GPS technology to precisely blast targets, and can travel through the air at 600mph
A spokesperson for Prime Minister Keir Starmer said his office would not be commenting on reports or operational matters.
Britain had previously said Ukraine could use Storm Shadow cruise missiles within Ukrainian territory but the government has been pressing the United States for permission to allow their use to strike targets inside Russia for several months.
Starmer yesterday hinted Ukraine would be able to use Storm Shadows as he rebuffed the Kremlin's scare tactics.
When quizzed on letting Ukraine use the UK-made missiles, the PM said: 'I've been doubling down in my clear message that we need to ensure Ukraine has what is needed for as long as needed to win this war against Putin.
'I am not going to go into operational details. You would not expect me to. The only winner in that would be Putin and it would undermine Ukraine.
'The single simplest way to end this conflict is for Russia to stop the aggression and to stop it today. We are on day 1,000 of that aggression'.
Storm Shadow - called Scalp by the French - is a weapon equipped with a navigation system that once launched, descends to a low altitude to avoid detection before locking onto its target using an infra-red seeker.
It comes after outgoing US President Joe Biden gave the war-torn country permission to use long-range missiles to strike deep inside Russia earlier this week.
It comes after outgoing US President Joe Biden gave the war-torn country permission to use long-range missiles to strike deep inside Russia earlier this week.
The decision was a major US policy shift and comes as Biden is about to leave office and President-elect Donald Trump has pledged to limit American support for Ukraine and end the war as soon as possible.
Britain's Storm Shadow missiles are capable of dodging air defences - making them a nightmare attack weapon for their enemy
The weapons are thought to be used in response to North Korea's decision to send thousands of troops to Russia in support of Russian President Vladimir Putin's invasion of Ukraine, according to one of the sources.
Around 10,000 soldiers from the communist regime have joined the fight to reclaim Kursk, which Ukraine seized in a daring counter offensive last August.
Biden hopes that this response will 'send a message' to Kim Jong Un not to send any more, sources said.
British Storm Shadow missiles have a range of up to 150miles, meaning Ukraine could now have the ability to strike targets inside Russia.
It comes just a day after Ukraine carried out its first strike on Russian territory with US-supplied long range missiles.
A massive explosion at an ammunition depot in Karachev around 75 miles from the Ukrainian border in Russia's Bryansk region illuminated the night sky yesterday morning on what was the 1,000th day of war in Ukraine.
Eyewitnesses along with Russian and Ukrainian military bloggers first reported the attack, with anonymous Ukrainian military officials later telling the strike was conducted with the US-manufactured ATACMS (Army Tactical Missile System).
This is a breaking news story. More to follow.