LONDON — British police arrested several men on suspicion of terrorism and explosives offenses Sunday and evacuated homes near an air base that the U.S. Air Force had been using to facilitate strikes on Iran.

A major incident was declared, with a massive emergency presence seen around RAF Fairford, which is about 90 minutes outside London, close to the village of Whelford in western England.

The Gloucestershire police force said it responded in the early hours of Sunday to reports of three suspicious vehicles moving toward the base, and arrested five men “on suspicion of committing offenses under the Explosives Act.”

Police did not provide further details on the men, who remain in custody, or what they were suspected to have done. “Work to establish the full nature of this incident is ongoing,” Assistant Chief Constable Richard Ocone said.

Deputy Assistant Commissioner Vicki Evans of Counter Terrorism Policing said the force is “working closely with our partners to understand the circumstances of the incident,” with the investigation still in its “early stages.”

Ocone said 85 homes across the local area were evacuated and a 440-yard cordon put in place while an Army ordnance disposal team examines the vehicles.

Helicopter footage from Sky News showed multiple white vans close to the base seemingly being searched by a bomb disposal robot.

Julian Tudsbery, who has lived in Whelford for 30 years, told Britain’s Press Association another resident had reported three suspicious vans in the village. Along with other residents, Tudsbery has since been evacuated to a nearby recreation center.

The Reuters news agency had reported that security measures at the air ‌base have been significantly increased in recent ‌days.

Cotswold District Council member Tristan Wilkinson told NBC News that a threat to the base from Iran about six weeks ago has heightened the alert level in the community and led to a ramped-up police presence and an increase in security patrols.

Wilkinson noted there is “a lot more vigilance from the local community” and that police in this instance “have done exactly what you’d hope they would do in increasing reassurance for the community.”

“This is a worry and escalation, and we wait to see what the nature of that actual incident is going to be,” the official added.

A U.S. European Command spokesperson said: “For operational security reasons we will not discuss specific force protection measures.”

“U.S. European Command remains vigilant and will take appropriate actions to ensure the safety and security of our U.S. service members, civilians, contractors, and their families across the European theater,” the spokesperson added. “We constantly assess a variety of factors that determine what measures we institute or modify to protect our installations, our people and their families.”

Asked about the incident Sunday after walking off Air Force One, President Donald Trump told reporters the arrest was an “amazing job.”

“They were looking to do big damage to our fort, and working with the British worked out great,” he said.

British Prime Minister Andy Burnham said in a post on X: “I know today’s incident near RAF Fairford will be deeply concerning for local residents and for many people following developments across the country.”

“The safety and security of the public is our first priority, and I want people to know that we will always take every step necessary to protect our communities and keep our country safe,” he added.

“The investigation remains ongoing, and I would urge people not to speculate while the authorities establish the full facts,” Burnham said.

In March, Keir Starmer, Burnham’s predecessor, gave permission for the U.S. to use its bases for “specific and limited defensive” operations against Iran.

In July, Iran’s ⁠Islamic Revolutionary Guard Corps warned Britain that “any base used to invade Iranian territory is our legitimate target,” Iran’s semiofficial Tasnim news agency reported, citing bomber aircraft flights from Fairford.

At the time, a British government spokesperson said that the country was “ready to keep the United Kingdom safe from any kind of attacks, whether it’s on our soil or from abroad.”

CORRECTION: (Sept. 28, 2026, 9:49 a.m. ET): A previous version of this article stated that the five detained had been charged. They have been detained but not charged.