The Middle East country launched two ballistic missiles at the joint UK-US Diego Garcia military base in the Chagos Islands, it was revealed on Saturday

Iran may have used a space launch vehicle to launch two ballistic missiles at the joint UK-US Diego Garcia military base, it has been claimed.

Details of exactly when the attack happened are tonight unclear, but the Ministry of Defence today said it was before Keir Starmer authorised an expansion of America's use of British sites on Friday. Neither warhead hit the facility on the Chagos Islands, in the Indian Ocean, after one reportedly failed in flight and the other was intercepted by the US.

It marks a worrying development for British military chiefs, amid fears the Iranian regime may have more military might than previously believed, with major European capitals, including Paris, potentially within its reach. It had been thought Iran's missiles have a range of 2,000km - 1,243 miles. But the Diego Garcia base is about 3,800km - 2,361 miles - from Tehran.

Experts, including retired Royal Navy commodore Steve Prest, believe Iran's Simorgh space launch vehicle may be capable of offering the extreme regime's leaders greater range. Mr Prest said: "Ballistic missiles are space rockets. They launch, they go really high up and they come down really fast. If you've got a space program, you've got a ballistic missile program."

Mr Prest said the launches were likely a message of defiance, to say "look what we can do." Justin Bronk, a senior research fellow at the Royal United Services Institute, a defence think-tank, added Simorgh could offer greater range "at the likely cost of terminal accuracy".

The Simorgh, also known as the Safir-2, is a 90-foot long two-stage, liquid-fuelled rocket designed to carry satellites into space. It was the first Iranian-made launch vehicle capable of placing multiple payloads into orbit.

Asked today if she is concerned Iran may have more powerful weapons than previously thought, Foreign Secretary Yvette Cooper said: "This is the latest in Iran's reckless strikes aiming at Gulf partners, at international shipping, at allies and at British interests as well.

She added: "That is why we have continued to support defensive action to support UK interests including offensive action against ballistic missile threats. We want to see as swift as possible resolution to this conflict, that supports regional security and stability, because that is what we need for UK security and for our economy as well."

General Sir Richard Barrons, former head of the Joint Forces Command, tonight claimed Iran's extreme regime has been "serially underestimated". And a foreign affairs analyst claimed a long-held assumption about Iran's missile capability "has just collapsed".

General Barrons said: "War generally does not follow a script and the enemy always gets a vote and, in this case, the enemy's vote, Iran, has been serially underestimated. We are where we are. This conflict and the way it has turned out now puts British interests and those of our allies at risk and ignoring it completely is no longer appropriate even if the decisions at the start of the conflict were very different.

"Iran and the UK have been at odds for a very long time. The Iranian regime regards the UK as an enemy and so if you are seen to participate in some fashion with this US-Israeli offensive action then they are clearly going to respond and we should not be surprised."

Foreign affairs analyst Nawaf Al-Thani added: "Iran may have demonstrated reach far beyond what much of the world believed it possessed. Paris comes into range. London moves much closer to the edge of vulnerability depending on launch point and payload.

"This would mean the missile threat is no longer confined to the Gulf, Israel, or parts of South Asia. It would mean the radius of deterrence, defense, and fear has expanded dramatically. If confirmed, Diego Garcia was not just a target. It was a message."

Defences at UK bases in the Gulf are understood to be at their highest levels amid fears of further retaliation as the US-Iran war continues.

The UN's nuclear watchdog today urged "military restraint" to avoid any risk of a nuclear accident" after Iran said its Natanz nuclear facility was targeted by strikes on Saturday morning. The Israel Defense Force (IDF) also claimed they carried out widescale air strikes in Tehran overnight, hitting dozens of targets, including sites used to produce critical components for ballistic missiles and rocket fuel.

It came after at least 640 strikes were carried out across 17 Iranian provinces on Friday, causing at least 68 casualties, the US-based Human Rights Activists News Agency (Hrana) said. Iran's Islamic Revolutionary Guard Corps (IRGC) yesterday said it had "pounded" air bases in Kuwait and the UAE, which it claimed are used by the US and Israel. The IDF also claimed it had identified missiles launched towards Israel on Saturday afternoon.

Meanwhile, the US military has claimed Iran's ability to threaten the Strait of Hormuz has been "degraded" since the US bombed an underground facility where they claim Iran stored cruise missiles and other weapons earlier this week. On Friday, the Prime Minister gave the US the green light to use British bases to strike Iranian missile sites attacking ships in the Strait of Hormuz.

Mr Starmer has repeatedly stood by his initial decision not to grant the US request to use UK bases to launch its initial wave of missile strikes against Tehran. Permission was granted for US jets to use British airfields for defensive operations only after Iran retaliated.

The move came after US President Donald Trump criticised Mr Starmer and the leaders of other Nato countries for not helping reopen the strait. Tehran’s throttling of the key oil shipping route, in retaliation to joint US-Israeli attacks on the regime, has sparked chaos for global markets.

Speaking on Friday, Trump had said the US was considering "winding down" military action and added his military was "getting very close" to meeting its objectives in the war. Asked about the decision to allow the US to use UK bases, Mr Trump said: “Well it’s been a very late response.” He added: “I was a little surprised at the UK, to be honest with you. They should have acted a lot faster.”

Iran’s foreign minister Abbas Araghchi had earlier warned that allowing British military bases to be used by US forces will be viewed as an act of aggression. The top Iranian official was said to have made the comment in a tense phone call with Yvette Cooper, the regime’s state media reported.

Asked today if Iran's attempted targeted attack on the Chagos Islands had any bearing on the UK's decision to allow the US to use its bases, Ms Cooper yesterday said: "Our approach to this conflict has been the same throughout. We were not, and continue not, to be involved in offensive action and we take a different view from the US and Israel on this.

"But we are supporting defensive action to support our interests and the UK national interests. That includes recognising Iran's escalating threat to international shipping, as well as their threat to our Gulf partners, none of whom were involved in the initial strikes as well. We want to see a swift resolution to this conflict because that is what is in everyone's interests."

Asked if the UK is being dragged into the war, Ms Cooper added: "As the Prime Minister has made clear, we will provide defensive support against these reckless Iranian threats. But we have not been and we continue not to be involved in offensive action and we want to see the swiftest possible resolution. As he's made clear we will not be dragged into a wider conflict."

A Ministry of Defence spokesperson said: “Iran’s reckless attacks, lashing out across the region and holding hostage the Strait of Hormuz, are a threat to British interests and British allies. RAF jets and other UK military assets are continuing to defend our people and personnel in the region. This government has given permission to the US to use British bases for specific and limited defensive operations.”