British police said on Tuesday they had re-arrested two men on suspicion of assisting Iranian intelligence as part of their investigation into activity at the RAF Fairford air base last month.
Counter Terrorism Policing said in a statement that they had re-arrested a 24-year-old British national, who was initially arrested outside the military base in southwest England in the early hours of September 27.
Police said they had also arrested a 25-year-old British-Iranian dual national who had previously been arrested in London.
Assistant Commissioner Laurence Taylor, Head of National Counter Terrorism Policing in the UK, said in a statement, "we consider it highly likely that there is Iranian state involvement."
British Prime Minister Andy Burnham last week said that the activity at RAF Fairford, which had been used by US bombers to carry out strikes on Iran, was likely to have been coordinated in Iran.