Counter-terrorism police are extending their questioning of the five suspects under the Terrorism Act after confirming that all the men arrested near RAF Fairford are UK nationals from London aged between 23 and 25. The men remain in custody on suspicion of Explosives Act offences and preparing a terrorist act, after police received a call around 12:45 a.m. Sunday reporting three suspicious vehicles heading toward the base.

Defence Secretary Wes Streeting declined to connect the arrests with the US-Iran war. "I don't want to draw a link between what's happening in Iran and this incident at this stage," Streeting said, adding it would be "very unwise" to speculate on the suspects' motives. He said actors backed by states seek to harm Britain. A source familiar with the investigation told Reuters an Iranian-linked motive is considered the most likely, with Russian sabotage and an Islamist plot also being examined.

UK authorities had been closely monitoring increased threats to the base and tightened security at the site before the attempted attack was foiled, according to people familiar with the matter. RAF Fairford, which hosts US B-1B bombers used in strikes on Iran this year, had been raised to FPCON Delta, the highest US force protection level, before the arrests. Army bomb disposal teams examined the three vans inside a 400 meter cordon, and about 85 households in nearby Whelford were advised to evacuate.