The British Prime Minister Said Iran Was Involved In the Air Base Incident. A UK-Iranian National Has Now Been Arrested.

A UK-Iranian national has been arrested in London on Thursday in connection with an incident at the Fairford air base this past weekend, British police said.

The 27-year old man was arrested in London, while another man has been questioned under caution. Two properties in the area have also been searched, the BBC reported. The men caught near the Royal Air Force base remain free on police bail.

The development comes shortly after British Prime Minister Andy Burnham said his government believes Iran played a role in the incident.

"There are strong indications that Iran played a part in what happened over the weekend at RAF Fairford," Burnham told the BBC earlier on Thursday. He did not elaborate on the claims.

Secretary of State Marco Rubio has also said that the incident involved a "foreign actor" but claimed he wouldn't "get into detail about that yet."

"I think it ties us to the reality here, and that is, we are dealing with elements in the world, and in the case of Iran, for example, who have openly threatened to attack American interests globally," Rubio said. "We're going to always take that very seriously. There will be repercussions for that, if it ever were to happen or even attempted."

Iranian Foreign Minister Abbas Araghchi rejected Burnham's claim, saying he is "barking up the wrong tree."

"I can confirm Iran's belief that releasing supposed terrorists working for foreign states really says it all," he added, in reference to the fact that the five suspects were released on bail earlier this week. Burnham said the men were subject to the "strictest possible bail conditions".

"The authorities have this under the strongest grip and closest control, and I can assure you of that," he added.

Early Sunday morning, five men described as British nationals between 23 and 25 were held on suspicion that they were planning to attack the airbase, which U.S. forces have used as a command outpost for strikes against Iranian targets.

A woman called police after she saw the men and three white vans parked on a road leading to the airbase. Counterterrorism police descended on the area and held the men on suspicion of planning a terrorist act. Images showed the men being detained and large black canisters on the road near the vans. Large amounts of fuel were found but there were no explosives in the premises.

Further reports noted that one of them men involved called emergency services himself before being arrested and one hour before a farmer also called the number to denounce their presence. The motive of the call is unclear.