Prime Minister Andy Burnham said Wednesday there are "strong indications that Iran played a part in what happened over the weekend at RAF Fairford."
"We have been waiting to confirm what we could say, but we can now confirm our belief that Iran played a part," Burnham told Sky News and the BBC.
He declined to explain the evidence, saying only that it remains an "ongoing, complex, and serious police investigation" and that more will be revealed in due course. British and U.S. officials are working closely together.
*What Happened*
The incident began at 1:30 a.m. Sunday when a farmer reported three white vans blocking a road near the base perimeter, with masked men nearby.
Counter-terror police arrested five British men, all from London aged 23 to 25, on suspicion of explosives offences and preparation of terrorist acts. A bomb disposal team was deployed.
Police later confirmed: no explosives were found. Only a quantity of petrol was recovered from the vans.
All five men were released on bail Monday under investigation, with strict conditions.
In a twist first reported by The Times, police believe the initial warning call to authorities came from one of the men who was later arrested — around an hour before police arrived.
*Why Iran?*
RAF Fairford has been used in recent months by U.S. bombers to launch strikes against Iran during the ongoing U.S.-Israel-Iran war that began in February.
U.S. Secretary of State Marco Rubio said the incident "clearly involves the hand of a foreign actor." President Donald Trump said the suspects "might be" connected to Iran and claimed there was a plan to cause "big damage."
Israeli Prime Minister Benjamin Netanyahu claimed Thursday Israel had provided Britain with intelligence about an "Iranian-sponsored attack."
On Thursday, counter-terror police arrested a sixth man — a 25-year-old dual UK-Iranian national in central London on suspicion of preparing terrorist acts. Two London properties were searched. He has since been released on bail.
*Iran Denies*
Iran has forcefully rejected the allegations.
Foreign Minister Abbas Araghchi told Britain it was "barking up the wrong tree," while Iran's embassy in London said it "categorically rejects and strongly condemns" speculation of involvement. Tehran has summoned the British ambassador.
Burnham chaired an emergency COBRA meeting Monday and defended the decision to release the suspects on bail, saying authorities have the case under "the strongest grip."
The investigation continues.