There is a "strong indication" that Iran played a role in Sunday's suspected terror plot near Royal Air Force (RAF) Fairford base in South West England, the prime minister confirmed Wednesday.
"There is indeed a strong indication that Iran played a part," Andy Burnham confirmed in an interview with Sky News.
However, he added: "This remains, though, a complex and very serious police investigation. So I can't say any more at this stage."
Five men from London, aged between 23 and 25, were arrested on suspicion of explosives offenses and terrorism.
The incident came after a farmer discovered three vans blocking a road near the RAF base in Gloucestershire at 1.30 am local time (0030GMT).
Later, it was understood that one of the suspects had contacted authorities around an hour before, a development first reported by The Times newspaper.
