London — 

British counterterrorism police said Tuesday they have rearrested two men in their investigation into last month’s incident at RAF Fairford in England, where US B-1 bombers were based.

A 24-year-old British national and a 25-year-old dual British-Iranian national were rearrested on suspicion of assisting Iran’s foreign intelligence service, police said in a statement.

“This is very much a live investigation, and our evidence gathering continues, but at this time our position remains the same; we consider it highly likely that there is Iranian state involvement,” said Laurence Taylor, a senior counterterrorism police officer.

Earlier this month, British Prime Minister Andy Burnham said that a suspected plot targeting RAF Fairford, a military base used by US forces in England, was “almost certainly directed by Iran’s Islamic Revolutionary Guard.” Iran has firmly rejected the accusations.

This is a developing story and will be updated.