A dual UK-Iranian national has become the sixth suspect to be arrested over an alleged terror plot near RAF Fairford.
The 25-year-old was arrested on Thursday afternoon in Westminster, central London, on suspicion of preparing terrorist acts.
Counter Terrorism Policing (CTP) searched two properties in the area as part of the investigation.
A second man, 26, who is a UK national, has also been questioned under caution, police said.
Five men in their 20s, who were arrested on Sunday, are still on police bail while the investigation continues.
Vicki Evans, senior national coordinator for counter terrorism policing, said: "The investigation into circumstances surrounding events in Gloucestershire is hugely complex, and our specialist teams are interrogating multiple lines of enquiry.
"As we've made clear, we're looking at all possible angles - including possible foreign state involvement.
"I'd like to thank the public for their continued support and patience whilst we work through this investigation."
The five previously arrested men - four of whom live in Westminster and one in Camden, north London - were detained early on Sunday after reports of "three suspicious vehicles" in the village of Whelford, near RAF Fairford.
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After the decision to release the five arrested suspects on bail, US President Donald Trump expressed surprise at the development.
In response, counter terror police said it was an "investigative decision" that was "grounded in experience and careful considerations of policing powers".
They added that no explosives were found in the vehicles, but a quantity of petrol was recovered.
Officers said they were considering whether a foreign state was involved in the incident. Prime Minister Andy Burnham added on Wednesday that Iran may have been involved.
Earlier on Thursday, Israeli Prime Minister Benjamin Netanyahu claimed Israel handed Britain intelligence about the suspected terror plot.
RAF Fairford has been used in recent months by US bombers after former prime minister, Sir Keir Starmer, granted the US permission to use British bases for "defensive" strikes against Tehran during the Middle East war.
(c) Sky News 2026: Counter terror police arrest UK-Iranian national over RAF Fairford investigation
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