Russia’s ambassador to the UK has declared that Ukraine’s use of Storm Shadow missiles on Russian territory means Britain ‘is now directly involved in this war’.

‘This firing cannot happen without NATO staff, British staff as well,’ Andrei Kelin told Sky News this afternoon – a day after British-made rockets battered a military base in Russia’s Kursk region.

His comments came as British and European leaders decried a ‘clear and deeply concerning escalation’ in the Ukraine conflict by Vladimir Putin after Russia’s forces appeared to strike the city of Dnipro with a suspected intercontinental ballistic missile (ICBM) this morning.

Sir Keir Starmer’s office said: ‘If (the suspected ICBM strike) is true, clearly this would be another example of grave, reckless and escalatory behaviour from Russia and only serves to strengthen our resolve.’

France’s foreign ministry echoed that sentiment, declaring that an ICBM launch ‘would be an extremely serious event’ as EU foreign affairs spokesman Peter Stano told reporters such an attack would be ‘yet another clear escalation from Putin’.

The scathing statements from European officials were made after horrifying footage emerged of what officials in Kyiv suspect were warheads from a Russian ICBM or advanced rocket raining down over Ukraine at 5:17am local time today.

‘Today, our crazy neighbour once again showed what he really is – and how afraid he is,’ Volodymyr Zelensky said.

The Ukrainian President said the missile’s speed and altitude match the profile of an ICBM after Kyiv’s air force reported the explosions were caused by such a weapon, though evidence has not yet been provided.

Russian authorities have thus far refused to comment, but if an ICBM strike is confirmed it would be the first time such a weapon has ever been deployed in combat.

Meanwhile, some analysts expressed doubt that Russian forces used a fully-fledged ICBM, arguing the reported range of the strike fell short of what would typically be expected of an intercontinental missile.

They pointed out that Moscow would have had to warn Washington to avoid triggering early warning systems and a possible response.

Security cameras caught the moment several projectiles streaked through the night sky and triggered a series of violent explosions in the city of Dnipro where the plants of state-owned aerospace and defence manufacturer Yuzmash are located.

Zelensky said experts were investigating the strike to try and identify the exact weapon used.

‘Expert examinations are underway. It is obvious that Putin is using Ukraine as a testing ground,’ Zelensky said in a video posted on social media.

The ferocity, speed and coordinated nature of the salvos suggested the explosions were caused by MIRVs (multiple independently targetable re-entry vehicles).

MIRVs are typically a feature of nuclear ICBMs designed for full-scale attacks on targets thousands of miles away, but analysts pointed out the nuclear warheads can be substituted for ‘weight simulators’.

Experts said the use of an ICBM or similarly advanced weapon to deliver a non-nuclear strike would be very costly, but would serve to illustrate how Moscow could dramatically escalate the conflict.

Dr Ruth Deyermond, Senior Lecturer in Post-Soviet Security at King’s College London, told MailOnline: ‘This strike has no obvious military value – they could achieve the same objectives without sacrificing (an ICBM or advanced missile).

‘It looks very much as if it’s signalling to the West what Russia could do if it chose to – launch a nuclear-armed missile. But it’s actually a sign of weakness,’ she added.

‘The Russian government knows what would happen to it if they did attempt to use any kind of nuclear weapon, so they have to resort to bluffing.’

Dr Mattias Eken, a defence and security analyst at RAND Europe, added: ‘The reported range of 700km falls short of the typical intercontinental range, casting doubt on its classification as a full-fledged ICBM.

‘If the missile was indeed an ICBM, Russia would have been required to provide advance notification to the US to prevent triggering missile warning systems and possible retaliatory actions.

‘Nevertheless, such a strike could have a symbolic value,’ he concluded.

‘It seems that the message that Putin and Russia is trying to send to the West is: we too have missiles that can strike anywhere in the world. Particularly after the US allowed ATACMS/Storm Shadow to target Russia, Putin may have felt compelled to demonstrate Russia’s ability to use long-range missiles as well.’

Footage of the strike was released as Russia also threatened to strike US air bases in Poland with ‘advanced weapons’ in an alarming statement this morning.

Healey said there were ‘unconfirmed reports – of Russia firing a new ballistic missile into Ukraine, which we know they have been preparing for months.’

Ballistic missiles can have a range of anywhere from under 500km (310 miles) to over 5,500km (3,400 miles) in the case of large intercontinental weapons.

As reports of the strike emerged this morning, Moscow said the opening of a new US ballistic missile defence base in Redzikowo near the Baltic coast will ‘increase the overall level of nuclear danger’, adding it could be considered a future target.

‘(The base) has been added to the list of priority targets for potential destruction which, if necessary, can be executed with a wide range of advanced weapons,’ Foreign Ministry spokeswoman Maria Zakharova concluded.

Zakharova’s statement came minutes after Ukraine’s air force first reported the possible ICBM strike, claiming it was fired from a base in Russia’s southern Astrakhan region on the Caspian Sea early this morning.

In a bizarre twist, Zakharova’s press conference was interrupted by a phone call in which the speaker appeared to tell the Foreign Ministry spokeswoman about the ICBM strike before instructing her not to comment on it.

A man’s voice was faintly heard saying: ‘Masha, ballistic missile strikes on Yuzhmash.

The Westerners are talking about it now. Don’t comment at all.’

This morning’s strike comes after Ukraine used US ATACMS and British Storm Shadow missiles to demolish targets inside Russia following approval by Sir Keir Starmer this week – something Moscow had warned for months would be seen as a major escalation.

Defence Secretary Healey refused to be drawn into confirming reports that Kyiv deployed the British long-range missiles, but said Ukraine faces a ‘serious moment’ in its defence against the Russian invasion.

The Prime Minister has meanwhile insisted UK support for Ukraine is ‘always for self-defence’ and compliant with international law, as he accused Putin of wanting ‘destruction not peace’.

Russia’s military has so far deployed smaller, slower Iskander missiles and a handful of hypersonic Kinzhal projectiles alongside hundreds upon hundreds of attack drones to destroy targets in Ukraine.

The advanced missile that struck this morning reportedly launched from the Kapustin Yar range in Astrakhan in Southern Russia – roughly 700km from Dnipro.

Putin’s forces used the region as a launchpad for strikes during the intervention in Syria in 2014.

Ukrainska Pravda cited anonymous sources saying the rocket may have been an RS-26 ‘Frontier’, a solid-fuelled, nuclear-capable rocket that was first successfully tested in 2012.

The Frontier missile weighs roughly 36 tonnes with a maximum range of up to 3,600 miles/5,800km. It flies at such a speed that Ukraine’s rudimentary air defence systems would be powerless to intercept its warheads.

‘If true this will be totally unprecedented and the first actual military use of ICBM. Not that it makes a lot of sense given their price and precision,’ Andrey Baklitskiy of the UN Institute for Disarmament Research posted on X.

The Russian attack targeted enterprises and critical infrastructure in Dnipro as well as other sites across the country, Ukraine’s air force said, at a time of escalating moves in the 33-month-old war.

The Kremlin deployed Tu-95MS strategic bombers to launch cruise missiles and MiG-31K fighters to fire hypersonic Kinzhal rockets in a calculated bid to plunge Ukraine into darkness as a bitter winter approaches.

In Dnipro, regional governor Serhiy Lysak said the missile attack caused damage to an industrial enterprise and set off fires. No casualty figures were available.

Some Russian missiles reportedly struck the towns of Kremenchuk and Myrhorod, while areas in Kyiv, Odesa and Sumy regions suffered blackouts as the electrical grid gave out.

The mass bombardment of Ukraine this morning prompted NATO to scramble F-16 warplanes over neighbouring Poland as ground-based air defence and radar systems were put on the ‘highest state of readiness’ amid the attack.

Ukraine’s air force reported air defences shot down six Kh-101 cruise missiles.

Responding to Zakharova’s statements on the opening of the Redzikowo air defence base, a Polish foreign ministry spokesman pointed out there were no nuclear missiles at the facility and that it is purely defensive in nature.

‘Such threats will certainly serve as an argument to strengthen Poland’s and NATO’s air defences, and should also be considered by the United States,’ added the spokesman, Pawel Wronski.

The facility, opened on November 13, forms part of a broader NATO missile shield called ‘Aegis Ashore’ designed to intercept short- and intermediate-range ballistic weapons.

Aegis Ashore constitutes a network of bases that use radar tracking systems from the US Navy’s Aegis warships to identify and shoot down oncoming missiles with American SM-3 rockets.

There are currently two sites online, one in Romania and one in Poland, reinforced by an early warning system based in Turkey and US Navy ships in Spain.

The wide-ranging attacks by Russia this morning come on Ukraine’s annual Day of Dignity and Freedom, honouring the beginning of its struggle for independence and liberty.

President Zelensky said in an address today: ‘We remember the real price of freedom for Ukraine.

‘And we do not forget all our people of different times who fought for Ukraine and became a model of dignity for the world.

‘Thanks to people, thanks to the desire of our people to preserve freedom and independence for Ukraine, our state will always be on the political map of the world. Always free and sovereign.’

The bombardment comes a day after Kyiv launched UK-supplied Storm Shadow missiles at targets in Kursk.

Fragments of the missiles that struck a military facility in the Russian town of Marino were recovered by military bloggers on Wednesday afternoon, with unverified pictures shared widely on social media.

The Mail understands the attacks, which followed Ukraine firing US-supplied ATACMS missiles on Tuesday, were personally approved by Sir Keir Starmer.

Russia this morning officially acknowledged the strikes, saying its air defences shot down two of the projectiles along with six HIMARS rockets and 67 drones.

Russian military bloggers said 18 Russian and North Korean servicemen were killed in that attack with dozens more injured, though the defence ministry has not commented.

Asked to confirm reports Storm Shadow had been used by Ukraine, Defence Secretary John Healey said: ‘I won’t be drawn on the operational details of the conflict.

‘It risks both operational security and in the end the only one that benefits from such a public debate is President Putin.’

According to Moskovsky Komsomolets, a Moscow-based newspaper, a Russian military expert had openly talked about retaliation for the Storm Shadow strike with an ICBM.

Timur Syrlanov, a Russian military analyst, said Ukraine should be ‘trembling’ over the use of the RS-26 ‘Frontier’ rocket.

‘In this situation, we will not use nuclear weapons, but the neo-Nazis and their Western allies, I think, will appreciate in the coming days the blow that will be dealt to Ukraine’s critical infrastructure and, possibly, to targets in Kyiv itself,’ he said.

‘Let them tremble, be afraid, and wait for landings anywhere. Moreover, the enemy understands perfectly well that our weapons can reach any targets throughout Ukraine.’

Putin on Tuesday signed off changes to the country’s laws on nuclear weapons to make it easier for them to be deployed against Ukraine.

And his foreign minister Sergei Lavrov chillingly warned that the strikes by Ukraine were a clear signal that Kyiv ‘wanted to escalate’ and that Russia would ‘react accordingly’.

The terrifying sabre rattling was confirmed by the Russian President’s close ally Dmitry Medvedev. Posting on X, the Deputy Chair of Russia’s security council said it meant ‘World War III’.

It came after Kyiv launched six ‘ATACMS’ rockets from an undisclosed location over the border into Russian territory on Tuesday.

The strikes triggered a fiery explosion at a depot in Karachev, believed to be storing ammunition supplied by North Korea, around 75miles from the Ukrainian border.

As tensions escalate in the Russia-Ukraine war, the UK’s Defence Secretary announced the British military would be hit by £500 million worth of cuts.

John Healy said the Labour Government would scrap six major programmes across the Armed Forces, including the Army’s main fleet of drones and two amphibious assault ships – HMS Albion and HMS Bulwark.

The plans have been criticised by former defence secretary Ben Wallace who argued they would send a message of weakness to the UK’s adversaries.

Writing in The Telegraph, he said: ‘For our enemies to be deterred they must know we intend to have no holes in our capabilities, or at least we will soon be upgrading them.

‘To tell the world we are scaling back our capabilities when our enemies are doing the opposite is pure folly.

‘No one is fooled by the tired and misleading excuse by Labour that ”we have to wait for a defence review” – yet another one.’

In videos recorded in the village of Marino in Russia’s Kursk region yesterday, multiple explosions were heard preceded by high-pitched whistling apparently from incoming missiles. The footage also showed smoke rising from buildings.

Unconfirmed reports suggested Ukraine had targeted an underground command and control facility 50 miles inside Russia with Storm Shadow missiles.

The navigational data and satellite intelligence which facilitated the air strikes was understood to have been provided by the US.

The strikes, which have not been confirmed by the British Government, follow the use of UK Storm Shadows to eliminate Russian military infrastructure in Crimea.

The significant difference is that while the UK regards occupied Crimea as Ukrainian sovereign territory, Kursk is recognised by Britain as belonging to Russia.

It is understood that the last time British weapons were used on Russian sovereign territory was during clashes between an Allied force and the Bolsheviks in the Arctic Archangel region in 1918-19.

Before that it was during the Crimean War in the 1850s.

Speaking in the Commons, Mr Healey declined to confirm the reports or divulge any operational details.

He told MPs: ‘We have seen over recent weeks a significant change in the [Russian] action and the rhetoric on Ukraine.

‘We as a nation and a Government are doubling down on our support for Ukraine and intend to do more.’