A branch of Iran’s Revolutionary Guard recruited British nationals for an operation involving a diversion near RAF Fairford, the Wall Street Journal reported, citing an official familiar with the intelligence. The British base is used by US bombers for operations against Iran. NBC News separately reported that intelligence reporting drove Prime Minister Andy Burnham’s assessment that Iran was likely involved in the weekend incident.

Iranian Foreign Minister Abbas Araghchi rejected Burnham’s allegation on Wednesday, pointing to the release on bail of all five suspects. “I can confirm Iran's belief that releasing supposed terrorists working for foreign states really says it all,” he said. “You're barking up the wrong tree.” Burnham had cited “strong indications” of Iranian involvement and defended the releases, saying the men faced “the strictest possible bail conditions.”

The five men, British nationals aged 23 to 25 living in London, were arrested Sunday on suspicion of explosives offences and preparing a terrorist act, then released Monday. Police found petrol but no improvised explosive devices in three vehicles and say the men remain under investigation. The Times reported that one suspect called police nearly an hour before a farmer separately raised the alarm; investigators are examining his reason for calling. NBC confirmed that two calls were made about the group.