British police were questioning five men on Monday after detaining them near RAF Fairford, a military airbase that has been used by the United States for strikes against Iran.
The men were detained in the early hours of Sunday after police received a report that three large white vans were heading towards the military airfield in western England.
The arrests were made amid heightened security concerns surrounding the base, with police investigating potential offences under explosives and terrorism legislation.
Investigation into possible motive
US President Donald Trump said the suspects had been planning to cause “big damage” and had been under investigation by British and US authorities.
However, a local farmer who alerted police said she had seen a group of “hooded and masked men” running into nearby fields.
British counterterrorism detectives have not publicly identified a suspected motive or said who they believe may have been behind the activity.
A source familiar with the investigation told Reuters that an Iranian-linked motive was being considered, while a possible Russian sabotage operation or a religiously motivated plot were also among the possibilities being examined.
Defence Minister Wes Streeting said he would not speculate about the motive while the investigation remained active.
Major incident declared at UK’s Fairford air base used by US forces
Speaking to BBC News, Streeting said the UK was aware of threats posed by Iran and groups linked to it.
“We know that Iran and their proxies wish to do us harm,” he said, adding that British authorities regularly work to prevent attempts to threaten the UK’s interests or those of its allies.
Britain imposed sanctions in May on 12 individuals and entities linked to Iran, accusing them of involvement in hostile activities, including alleged attack plots and financial support for groups seeking to destabilise the UK and other countries.
Iran has repeatedly denied involvement in attacks or plots in Britain and elsewhere.
RAF Fairford cordoned off
The British government has authorised the United States to use bombers based at RAF Fairford to conduct strikes against Iranian missile sites that were attacking ships in the Strait of Hormuz.
Iran’s Islamic Revolutionary Guard Corps warned Britain in July against allowing US bombers to operate from Fairford, saying bases used to launch attacks would be considered legitimate targets.
Police imposed a 400-metre cordon around the RAF Fairford site following Sunday’s arrests and evacuated residents from 85 homes.
A bomb disposal robot was seen operating near the three white vans, while armed officers guarded the main entrance to the base. Heavy machinery was also used to block other access points.
Security measures were also increased at other US military bases in Britain.
The government said Prime Minister Andy Burnham was being regularly updated about the incident and had cancelled at least two engagements at the Labour Party’s annual conference on Sunday.
