British police have arrested a 25-year-old dual British-Iranian national on suspicion of preparing terrorist acts in connection with an incident near RAF Fairford.

The man was arrested in Westminster, London on October 1. Police also searched two residential properties in the area, according to BBC.

Five British men in their 20s who were arrested on September 27 near the airbase in Gloucestershire remain on bail as the investigation continues.

Counter-terrorism police are examining a range of possible explanations, including potential involvement by foreign states, said Senior National Coordinator, Deputy Assistant Commissioner Vicki Evans.

“The investigation into the circumstances of the events in Gloucestershire is extremely complex, and our specialist teams are examining numerous lines of inquiry,” Evans said.

The arrests and searches are part of an ongoing investigation into the incident near RAF Fairford.