British counterterrorism authorities are investigating an apparent plot near RAF Fairford, a British air base used by the United States, after five men were arrested early Sunday and three suspicious trucks were found near the facility.
London’s Metropolitan Police, which leads investigations involving suspected terrorism, said authorities were alerted at approximately 12:45 a.m. to three vehicles that appeared to be heading toward RAF Fairford. The British-owned installation has been operated by the United States under an arrangement dating back to the Cold War.
The arrests come amid heightened concern in Britain over operations conducted by hostile foreign states and their proxies. British authorities have repeatedly identified Russia and Iran among the countries accused of using proxies to carry out criminal activity inside the United Kingdom.
Officials said in March that national security investigations involving hostile-state activity, including cases connected to Iran, had risen by 50% during the six-month period ending in December 2025.
RAF Fairford has been used by American bombers conducting narrowly defined strikes against Iranian missile sites. Those operations were carried out under an agreement reached with then-British Prime Minister Keir Starmer, who subsequently expressed opposition to the war launched by the United States and Israel on February 28.
Investigators are reportedly examining a possible Iranian connection to the incident, although no determination has been announced. Tehran has previously maintained that military installations used to launch attacks against Iranian territory can be considered legitimate targets.
President Trump praised the law enforcement and security personnel involved in intercepting the suspects, saying they had been under surveillance before their arrests.
“It was an amazing job. We had them under investigation. They were looking to do big damage to our fort. And working with the British worked out great,” he told reporters in Chicago on Sunday. “We had them under view for a long time and we got them.”
The five suspects were first taken into custody on suspicion of violations of Britain’s Explosives Act in the Whelford area, which borders RAF Fairford. The installation houses the headquarters of the U.S. Air Force’s 501st Combat Support Wing as well as the 420th Air Base Squadron.
Aerial video broadcast by Sky News showed what appeared to be a bomb-disposal robot operating among three white trucks. The rear doors of two vehicles were open, with large black objects visible nearby, while the robot appeared to be attempting to gain access to the third vehicle.
Authorities have not released the nationalities of the five suspects. Under Britain’s Terrorism Act 2000, individuals arrested on terrorism suspicions may be held for as long as 14 days without being charged, significantly longer than the ordinary 24-hour detention period unless authorities obtain an extension.
“We are in the early stages of an investigation, and five men remain in custody,” said Vicki Evans, the Met’s counterterrorism policing senior national coordinator.
Evans said authorities established a 400-yard security perimeter around the three suspicious vehicles while British military personnel carried out examinations. Approximately 85 households were evacuated as a precaution, with some displaced residents being brought to a nearby recreation center.
The U.S. Embassy in London also issued a warning to Americans, urging them to exercise caution and remain attentive to their personal security.
British Prime Minister Andy Burnham acknowledged that news of the incident would be “deeply concerning” to many people. In a social media post, Burnham expressed appreciation to police and military personnel responding to the scene and thanked residents forced to leave their homes “while precautionary checks are carried out.”
Burnham also appealed to the public “not to speculate while the authorities establish the full facts.”
War Secretary Pete Hegseth and British defense chief Wes Streeting have also discussed the developing situation.
British security authorities have previously accused proxies connected to Iran of involvement in attempted arson and sabotage operations in Britain and elsewhere, including incidents directed against Jewish targets. Officials have warned that Tehran could broaden the range of potential targets inside Britain if Middle East hostilities continue.
Gloucestershire Police said the immediate situation appeared to be “contained” while urging residents in the area to continue following instructions from authorities as the investigation proceeds.
Julian Tudsbery, a Whelford resident for three decades, said another person in the community had spotted three “suspicious vans” in the village during the early hours of Sunday. Tudsbery said police subsequently arrived and ordered residents to leave.
“There were several police, three police cars in the drive, and they said you need to evacuate, there’s been a major incident, said he couldn’t elaborate,” he said.