Aerial images show white vans in a wooded area near RAF Fairford during the emergency response.
Counter-terror police are investigating suspicious vehicles near the Gloucestershire airbase, with five men in custody and residents facing a night away from home.
Five men have been arrested on suspicion of preparing a terrorist act and explosives offences after police received reports of three suspicious vehicles travelling towards RAF Fairford in Gloucestershire.
The report, made at about 00:45 BST on Sunday, triggered a major incident response and the evacuation of homes in nearby Whelford. Counter-terror police are leading the investigation, while an Army explosive ordnance disposal team has been examining vehicles near the airbase.
Police said all five suspects remained in custody on Sunday evening. Investigators described their work as being at an early stage, while Gloucestershire Constabulary’s temporary Chief Constable Maggie Blyth said she believed the incident was contained.
Explosives team examines vehicles
Emergency services established a 400-metre cordon around the affected area. A hazardous area response team was also deployed as part of the operation near the base, which is used by the United States Air Force.
Aerial images showed a remote-controlled robot approaching stationary white vans in a wooded area. Police had not confirmed its use.
Gloucestershire police initially detained the men on suspicion of offences under the Explosives Act. They were subsequently further arrested on suspicion of preparing a terrorist act.
At a news conference late on Sunday, Blyth was asked whether officers were looking for anyone else. She said she believed the matter was contained, as Counter Terrorism Policing and local officers continued their inquiries.
Whelford residents evacuated
A local woman said she alerted police after seeing three parked vans and a group of masked men near the base early on Sunday. She said she first tried to reach Ministry of Defence police but received no answer, before calling 999. The ministry declined to comment.
Residents described being moved out of their homes during the emergency response, with some taken to a leisure centre. In Whelford, 85 households were advised to evacuate.
Julian Tudsbury said police woke him at about 07:00 by banging on his door. He described several officers and three police cars in his driveway, and said he was told to leave because of a major incident, without further details being provided.
Another resident, identified only as Jeff, said shouting woke him at about 02:00. Looking outside, he saw men being held by armed police near his home.
Gloucestershire police later told evacuated residents they would not be able to return on Sunday night. District council deputy chief executive David Stanley said overnight accommodation would be arranged for anyone unable to stay with friends or relatives.
US military remains vigilant
RAF Fairford has longstanding links with the American military and has recently served as a staging point for US warplanes carrying out defensive strikes on Iran.
US President Donald Trump said those arrested had intended to cause significant damage and claimed they had been under observation for a long time. Police, meanwhile, continued to describe the investigation as being in its early stages.
A US Air Force spokesperson said personnel remained vigilant but declined to discuss specific security measures.
The US Department of Defense also raised the threat level at RAF Lakenheath in Suffolk to its second-highest category. That base hosts the US Air Force’s 48th Fighter Wing.
