British counter-terrorism police are investigating a “major” incident near RAF Fairford.
Five men were arrested on suspicion of preparing a terrorist act.
Police were called early Sunday after reports of three suspicious vans apparently heading towards the Gloucestershire airbase.
Officers detained the men, initially under explosives-related offences, while bomb disposal teams examined the vehicles.
About 85 homes in nearby Whelford were evacuated as a 400-metre security cordon was established.
Residents were taken to a leisure centre while specialists inspected the scene using a bomb-disposal robot.
What Triggered Such A Major response?
Police said the incident had been “contained”, while government officials said emergency teams acted quickly to protect residents.
Defence Minister Wes Streeting added: “We can be reassured that this is being dealt with.”
RAF Fairford hosts the US Air Force’s 501st Combat Support Wing.
The US unit said none of its personnel were involved and that it remained closely coordinated with British authorities.
The arrests come amid wider UK concerns over suspected hostile-state activity, including reported drone sightings around military sites.
British officials have previously accused Iran and Russia of using proxies for criminal operations in Britain, claims Moscow denies.
For investigators, the immediate priority is clear: determine who the suspects are and what they intended.
Investigators must also determine why Fairford was allegedly their target.
