A major incident has been declared at RAF Fairford after ‘several’ men were arrested and homes were evacuated.
The men were arrested on suspicion of offences under the Explosives Act as armed police swarmed the US air base and reportedly checked nearby cars for bombs.
It is understood other US bases have been put on Delta alert, the highest threat level that can be issued by Washington’s Department of Defense.
Residents living near RAF Fairford are being evacuated to a leisure centre as the British Army’s specialist explosive ordnance disposal team examine vehicles near the base amid what is understood to be a possible car bomb threat.
Roadblocks and armed police have been in place near the Cotswold base in recent days and emergency vehicles are parked nearby.
A witness said armed police had blocked access to the base’s main gate and around 30 police cars, ambulances and fire engines were in the village of Fairford.
Earlier a vehicle, apparently a tractor, was pictured blocking a gate at the base.
Gloucestershire Police said: ‘A number of properties are currently being evacuated in the Whelford area following the declaration of a major incident.
Armed police at RAF Fairford as a major incident was declared and several men were arrested under the Explosives Act
Officers have also evacuated nearby homes, with residents ushered to a leisure centre.
A B-1B Lancer bomber pictured at the air base, the home of the US Air Force’s 501st combat support wing
‘It follows the arrest of several men on suspicion of offences under the explosives act.
‘The Army’s specialist explosive ordnance disposal team are currently examining a number of vehicles.
‘The local residents are being evacuated to a nearby leisure centre.
‘A cordon is currently in place but we’d like to reassure people that we believe this incident is contained.
‘We are working closely with our partners and are enacting the well-rehearsed plans we have in place.’
The major incident was declared as the Labour party conference began in Liverpool and will raise fresh questions over the thorny decisions to be made on defence by Prime Minister Andy Burnham and his Chancellor John Healey next month.
RAF Fairford is home to the headquarters of the US Air Force’s 501st combat support wing, its only such unit and the ‘preferred bomber forward operating location in Europe for USAF Global Strike Command’.
The air base was the subject of a warning from Iran’s Revolutionary Guard in July as the regime warned Britain not to allow US bombers to fly from the base.
Westminster permitted US planes to carry out defensive strikes on Iranian missile sites that had been attacking ships in the Strait of Hormuz.
Ministers have also briefed bosses of critical national infrastructure of the threat posed by Russia, Reuters reported.
The Government is understood to be increasingly concerned about possible sabotage efforts and cyber attacks by Moscow, though the Kremlin denies any such activity.
A US Air Force spokesman said: ‘The 501st Combat Support Wing and our fellow UK-based Wings remain vigilant and will take appropriate actions to ensure the safety and security of our US service members, civilians, contractors, and their families.
‘We constantly assess a variety of factors that determine what measures we institute or modify to protect our installations, our people and their families.’
In June the US government said it would spend around $500million (£377million) on ‘expansion and military infrastructure’ at the base, understood to include a new hangar complex.
And in May the Royal International Air Tattoo, set to be held at the base, was cancelled after the Royal Air Force Charitable Trust Enterprises said the ‘escalating geopolitical situation in the Middle East’ had required a ‘significant increase in real-world operational missions’ from RAF Fairford.
