British police have arrested a man with dual British and Iranian citizenship in the investigation into the alleged plot near RAF Fairford base

British counterterrorism police arrested a 27-year-old dual British-Iranian national in Westminster on Thursday, suspected of preparing terrorist acts as part of an investigation into an alleged plot near RAF Fairford air base in western England.

The suspect was detained under Section 5 of the Terrorism Act 2006. A second man, a 26-year-old British national, was questioned under caution. Police also searched two properties in Westminster.

The investigation began on Sunday, when five men aged between 20 and 30 were arrested in the village of Whelford, near the RAF base, after suspicious vans were spotted. They were suspected of terrorism and explosives-related offences, but were released on bail the following day.

Authorities are examining several leads, including the possibility of foreign state involvement. RAF Fairford is used by U.S. forces for operations related to Iran. The incident prompted a major security operation, but its circumstances remain largely unclear.