UK says strong indications Iran involved in RAF Fairford airbase incident

British Prime Minister Andy Burnham said on Wednesday there are "strong indications" Iran was involved in the RAF Fairford airbase incident in southwest England. The bomb scare on Sunday triggered a major security response at the base, which the US military uses in its war against Iran.

What happened at RAF Fairford?

Three white vans appeared to head towards RAF Fairford in the early hours of Sunday, in what became a major security incident. A local resident who rang the police said she saw a group of masked men near the vans. The vans were blocking a road in a village next to the military base.

Police arrested five British men on Sunday on suspicion of explosives and terrorism offences. Officials have not explained the nature of the threat.

What did Burnham say about Iran's involvement?

"There are strong indications that Iran played a part in what happened over the weekend at RAF Fairford," Burnham told the BBC. He described it as an ongoing, complex and serious police investigation. His comments are the first official confirmation from UK authorities that Iran may have had a hand in the incident.

"We have been waiting to confirm what we could say, but we can now confirm our belief that Iran played a part," Burnham told Sky News. Iran's embassy in London earlier said it "categorically rejects and strongly condemns" speculation that it was involved.

US President Donald Trump and Secretary of State Marco Rubio had previously indicated that intelligence bodies were aware of the suspects and that a foreign state could be involved. UK officials had not weighed in until now.

Why is there confusion over the RAF Fairford investigation?

The case was plunged into confusion when police released on bail the five British men arrested on Sunday. After three days of investigations, including the use of a bomb disposal team, police said on Tuesday that no explosives were found in the vehicles. They did retrieve a "quantity of petrol".

On Wednesday, The Times newspaper reported that the incident had been foiled after one of the five suspects tipped off the police before the group was apprehended.

Why is Iran linked to RAF Fairford?

Speculation was rife that Iran or another hostile state could have been involved, after Tehran previously warned London against allowing its military bases to be used by Washington. Britain gave the US the greenlight to use RAF Fairford for defensive strikes against Iran. The decision drew Tehran's ire and unease from some residents in the Gloucestershire countryside where the base is located.