British police have arrested several men on suspicion of explosives offences near an RAF airbase in England which is used by the US air force.
It comes as army bomb disposal experts searched vehicles and homes which were evacuated in the “major incident” today.
The British government, which gave authorisation to the US to use RAF Fairford to strike Iranian missile sites that were attacking ships in the Strait of Hormuz, said Prime Minister Andy Burnham was being updated about the incident.
Iran’s Revolutionary Guards had warned in July that any base used in strikes would be a legitimate target.
A Reuters eyewitness said armed police had blocked access to the main gate of the base, while machinery had been positioned in front of access points.
Residents of a nearby village were woken in the early hours and ordered to leave their homes.
Around 30 emergency vehicles, including police cars, ambulances and fire engines, were parked up in the village of Fairford near the base, while a helicopter flew above.
In a statement, Gloucestershire police said: “A number of properties are currently being evacuated in the Whelford area following the declaration of a major incident.
“It follows the arrest of several men on suspicion of offences under the Explosives Act,” it said, referring to a village near the air base.
“The Army’s specialist explosive ordnance disposal team are currently examining a number of vehicles.”
Police said they believed the incident was now contained.
A US Air Force B-1 Lancer bomber is pictured on the tarmac at RAF Fairford base in Fairford
The British government said it would be inappropriate to comment whilst investigations are ongoing.
A spokesperson for the US Air Force declined to discuss specific force protection measures.
“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,” the spokesperson said.
“We constantly assess a variety of factors that determine what measures we institute or modify to protect our installations, our people and their families.”
Britain said in July its armed forces were ready to protect the country from any attack after Iran’s Revolutionary Guards warned the UK not to allow US bombers to fly from Fairford.
Media reports said security had been increased at other bases used by the US in Britain, including at Lakenheath and Mildenhall.
British ministers have also previously briefed providers of critical infrastructure on the threat posed by Russia, with the government increasingly concerned about possible sabotage operations and cyberattacks.
Russia denies mounting hybrid attacks on Western nations.