Counter-terrorism police are investigating whether Iran is behind a suspected bomb plot after armed officers found explosives on three vans parked minutes from an RAF base used by the US military.
The Guardian understands that after five men were arrested on terrorism charges, investigators were examining materials found in the vans, with an initial view being they were consistent with improvised explosive devices.
Images circulating on Sunday showed shirtless men being handcuffed in a dark country lane in the early hours of Sunday after police were called to reports of three suspicious vans travelling towards RAF Fairford in Gloucestershire, which hosts US air force missions against Iran.
The suspected plot appears to have been foiled by chance when a member of the public spotted unusual behaviour late at night in the countryside from a group of men and called ۹۹۹.
During the major incident the residents of ۸۵ households in the Cotswolds village of Whelford were rapidly evacuated to Cirencester leisure centre and a ۴۰۰m cordon was placed around the white vans as robots from the army’s bomb squad examined them.
Tests were ongoing to find out whether the suspected explosive devices were viable, with bomb robots deployed in the Gloucestershire countryside as investigations continued.
After their initial arrest over explosives offences, the five men detained early on Sunday were further arrested later in the day on suspicion of the preparation of a terrorist act. The pictures of the men with their shirts off could point to a precautionary measure against the risk of suicide vests or concealed weapons.
At least one van carried the logo of a fuel company and a phone number missing a digit. A real fuel company of the same name firmly rejected any connection to the incident and said: “We are extremely concerned that our company’s name has been used without our knowledge or permission.” It said it was cooperating with the authorities.
In a statement, counter-terrorism police said: “At around ۱۲.۴۵am today (Sunday ۲۷ September), police received a call relating to three suspicious vehicles which appeared to be travelling towards the airbase.
“Armed officers responded and five men were arrested in the Whelford area on suspicion of committing offences under the Explosives Act. They were further arrested on suspicion of preparation of a terrorist act, contrary to section ۵ of the Terrorism Act.”
The arrests come as the war between the US and Iran limps on. In July Iran’s Islamic Revolutionary Guard Corps noted RAF Fairford’s use by US bombers, warning the UK that “any base used for aggression against Iranian territory constitutes a legitimate target for our forces”.
Counter-terror police and the security services are searching for the motive. The circumstances of the arrest near the base and prior warnings from Tehran leave an Iranian motive high in the investigators’ and government’s thinking. But sources warn nothing is being ruled out, including a jihadist or other motive, and the UK threat level remains at severe, the second highest, meaning an attack is highly likely.
Whether there was any foreign involvement forms part of the investigation, and Iran’s ministry of intelligence and security has orchestrated attacks overseas before.
Any proven link with Iran would be a dramatic escalation in hostilities between the UK and Tehran. While several recent incidents in the UK have been linked to the Middle-Eastern country, including the antisemitic arson attack on four Hatzola ambulances in Golders Green, the alleged plot at RAF Fairford appears to be significantly more serious.
And it raises urgent questions for the UK security services after it appeared the authorities had been unaware of the alleged plot, with police only moving on the three vans after a ۹۹۹ call from a resident who spotted them as she drove home.
The US president, Donald Trump, claimed to have had the suspects under view for a “long time” and alleged the men “were looking to do big damage” – although the Guardian understands the operation was not intelligence-led, suggesting investigators had not known about any potential plot in advance.
“It was fantastic. Working with Britain, it was an amazing job,” Trump said.
The UK prime minister, Andy Burnham, was being updated on the matter from Liverpool, where the Labour party conference is taking place. He cancelled plans to take part in a journalists versus politicians football match in order to take calls about the incident.
He said it was “deeply concerning” and the government will “always take every step necessary” to protect people.
Fairford has a particularly long runway, which extends almost ۲ miles (۳km). It is reinforced to support heavy bombers such as the B-۱ and B-۵۲, which have been deployed in attacks on Iran. The aircraft are capable of carrying large payloads, including “bunker buster” bombs.
In March this year, after then prime minister, Sir Keir Starmer, granted permission for “defensive” US action against Iranian missile sites from UK bases, four American bombers landed at RAF Fairford and the US started using British bases for “specific defensive operations”.
There have been protests in recent months over the UK government’s decision to allow the US to use RAF Fairford to carry out strikes on Iranian missile sites that are attacking ships in the strait of Hormuz.
At the time of Iran’s warning in July, a government spokesperson said: “Our armed forces are ready to keep the United Kingdom safe from any kind of attacks, whether it’s on our soil or from abroad. The UK stands ready ۲۴/۷ to defend itself.”
Evacuated residents of Whelford spoke of “heightened tensions” in recent weeks around the base with more frequent, visible police patrols.
Outside Cirencester leisure centre, Jason, a resident of Whelford who declined to give his surname, said: “There have been heightened tensions recently around the base, we are aware it is used by the USAF … It always feels pretty safe. Some residents have seen increased police patrols.”
It was unclear when people would be able to return to their normal lives; those at the leisure centre said they had been asked by authorities if they had anywhere else to stay on Sunday night.
The Fairford youth football club, about ۱.۵ miles (۲.۴km) north-west of Whelford, was taken over as a temporary base for the emergency service response to the incident. There were several police vehicles, ambulances, fire engines, pop-up tents and a large mobile command-unit vehicle in the grounds.
Richard Ocone, the assistant chief constable with Gloucestershire constabulary, said: “We appreciate the disruption this will have caused and would like to reassure them we are working as quickly as we can to get them back in their properties.”
