LONDON, Oct 3 — A UK-Iranian dual national arrested over a mysterious incident near a British military airbase has been released on bail, counter-terrorism police said on Saturday.

The 25-year-old was arrested in central London on Thursday “on suspicion of preparation of terrorist acts” as part of an investigation into events near RAF Fairford in southwest England on Sunday.

Five other men arrested on suspicion of explosives and terrorism offences near the airbase in Gloucestershire were also released on bail earlier this week.

UK Prime Minister Andy Burnham has said there were “strong indications that Iran played a part” in the incident, a claim Tehran has rejected.

But the source and nature of the threat near the airbase – used by the US military in its war against Iran – have remained shrouded in mystery.

Police were called to the base early on Sunday after reports that “suspicious” white vans were heading towards it, triggering the evacuation of a nearby village and the declaration of a “major incident”.

Days later, police said no explosives had been found at the scene.

Adding to the mystery, British media reported that officers were alerted to the incident by one of the initial suspects, although police have not commented on the reports.

Washington has further muddied the waters by criticising the release of the suspects on bail and declaring hostile state involvement early in the investigation.

“The investigation into the circumstances surrounding events in Gloucestershire is continuing,” UK police said in an update on Saturday. — AFP