Two men have been re-arrested over an alleged plot near RAF Fairford, police said.
Counter Terrorism Policing re-arrested two men on Tuesday as part of the investigation into activity near RAF Fairford last month.
A 24-year-old UK national and a 25-year-old dual UK and Iranian national, both from the Borough of Westminster, London, were arrested on suspicion of assisting a foreign intelligence service.
The country to which the investigation relates is Iran, police said.
The 24-year-old man was initially arrested on 27 September near RAF Fairford in Gloucestershire and the 25-year-old was later arrested on 1 October in Westminster, central London.