UK-Iranian man arrested in RAF Fairford investigation

British counter-terrorism police have arrested a 27-year-old UK-Iranian dual national on suspicion of preparing terrorist acts in an investigation into an incident near RAF Fairford, an airbase in southwest England. Police are examining possible foreign state involvement but have not identified who was responsible.

Police announced the arrest on Thursday. The man was detained in Westminster, central London, and a second man, a 26-year-old UK national, was questioned under caution. Two properties in the area were searched, the BBC reported. Police did not say when the 27-year-old was arrested.

The announcement came days after five other men were arrested near the base in the early hours of Sunday. All five were released on bail Monday and remain on police bail.

Police made the earlier arrests after being alerted to three suspicious vehicles in Whelford, a village directly east of RAF Fairford, according to the BBC. The five men, all UK nationals from London, were initially arrested on suspicion of explosives offences and later on suspicion of terrorism offences.

The BBC reported that the men are between 23 and 25 years old. Four live in Westminster and one in Camden. Officers searched their homes separately from the searches of two properties reported in connection with the latest developments. Police found a quantity of petrol but no explosive devices during searches of vans near the base, the BBC said. Officers described the decision to release the five men on bail as an “investigative decision” grounded in “experience and strategy”.

“The investigation into circumstances surrounding events in Gloucestershire is hugely complex, and our specialist teams are interrogating multiple lines of enquiry,” Vicki Evans, the Metropolitan Police’s senior national coordinator for counter-terrorism policing, said in a statement quoted by Al Jazeera.

“As we’ve made clear, we’re looking at all possible angles – including possible foreign state involvement,” Evans said. Police have not publicly attributed the incident to Iran.

UK Prime Minister Andy Burnham earlier said there were “strong indications” Iran played a role in the alleged incident, according to Al Jazeera. Iran strongly denied involvement, and its foreign minister, Abbas Araghchi, rejected Burnham’s allegation.

RAF Fairford is about 160 kilometres (100 miles) west of London. Al Jazeera reported that U.S. bombers have used the base during decades of conflicts in the Middle East. The BBC said it has served as a forward operating location for the U.S. Air Force for decades.