The alleged RAF Fairford bomb plot was brought to police attention after one of the five suspects called 999 himself, it has emerged.
Armed officers were sent to the Gloucestershire airbase in the early hours of Sunday, where they detained the men and removed their clothing amid fears they could be wearing suicide vests.
Police later confirmed that no improvised explosive devices had been found in the three vans involved. However, a quantity of petrol was recovered from the vehicles.
Laurence Taylor, head of Counter Terrorism Policing, said the five men had been released on police bail and remained under investigation, subject to strict conditions.
He said the decision to release them was an investigative one, based on “experience and careful consideration of policing powers”.
Investigation into RAF Fairford incident
The reason one of the suspects made the emergency call remains under investigation. Detectives are examining whether he was attempting to withdraw from the alleged plot or whether the call formed part of a wider plan.
Another line of inquiry is whether the incident was intended as a stunt or a message to British and US authorities, rather than an attempted attack.
A farmer who encountered suspicious vans near the base reported seeing between eight and ten masked men moving through woodland and fields. It is now understood that the figures she saw in the darkness were armed police responding to the incident.
Five British men from London, aged between 23 and 25, were arrested on suspicion of explosive and terrorism offences near RAF Fairford. They were all released on bail within 36 hours.
The residents of 85 homes in the nearby village of Whelford were allowed to return on Monday after items described as explosives were assessed as not viable.
Searches of the men’s London homes have been completed, while police cordons near the base are expected to be removed.
RAF Fairford is used by the US Air Force to conduct strikes against Iran. Tehran has “categorically” denied involvement in the suspected plot and criticised the circulation of what its embassy called “fabricated speculations”.
US Secretary of State Marco Rubio said the incident “clearly involves the hand of a foreign actor”, but stopped short of directly blaming Iran. He said the Iranian regime had “openly threatened to attack US interests globally”.
Former US president Donald Trump said on Tuesday that he was surprised the men had been released and suggested they were already known to the authorities.
The alert level at the US airbases at RAF Lakenheath and RAF Mildenhall in Suffolk was raised to “Charlie”, the second-highest level, following the incident. Residents near RAF Fairford had earlier said armed officers told people to remain indoors because an attack was imminent.
