British counterterrorism police arrested five men early Sunday near RAF Fairford after a tip-off about three suspicious vans heading toward the US-used airbase. Officers made the arrests under the Explosives Act and on suspicion of preparing a terrorist act.

Police received a call at about 12:45 a.m. Armed officers detained the men near Whelford village, and Army bomb disposal teams examined the vans. About 85 homes were evacuated as a precaution, and police said the incident was contained.

US President Donald Trump said the suspects were looking to do "big damage" and had been under investigation by British and US authorities. An Iranian-linked motive is being examined as the most likely, according to a source cited by the Telegraph, though police have not publicly confirmed who was involved.

Iran's Revolutionary Guard threatened in July to strike RAF Fairford, which US aircraft have used in operations against Iranian sites. Investigators are also weighing other motives.

What happens next: the five men can be held up to 14 days under counterterrorism law as detectives continue the inquiry.