Trump says US moved their B-1 bombers from RAF Fairford airbase after additional threats were made

US President Donald Trump said on Monday that the United States had withdrawn all B-1 bombers from a British airbase because of unspecified threats that he believed were linked to Iran.

The Pentagon confirmed earlier that the bombers had left the RAF Fairford airbase – used by the United States to launch ‘defensive’ strikes on Tehran – even as the British government insisted the site was safe.

"There were some threats," Trump told reporters at the White House.

"And rather than tempting the enemy – we'll capture the enemy and beat the enemy, but why should we leave them there? So we moved them around a little bit, not very far."

Speculation has swirled about the incident since police were called to the base in southwest England on 27 September after a local farmer reported a group of men with several vans engaged in "suspicious" activity.

Despite a major counter-terrorism probe, five suspects arrested at the time and a British-Iranian national detained afterwards have all since been released on bail.

Investigators did not find any explosives in the vans, but "a quantity of petrol was recovered," according to counter-terrorism police.

Trump would not comment on a report that the threat involved attack drones, saying: "I can't tell you that but if they did they'll suffer greatly."

"We actually know the people that made the threat," said Trump, adding: "They would be linked to Iran."

Two US officials told US media outlets that the bombers were moved after commanders received new threats about an Iran-backed plot.

One US official said the new information was part of the same threat warnings that surfaced three weeks ago, but the situation became urgent in the past 24 hours.

Asked whether the base was safe however, UK Prime Minister Andy Burnham's official spokesman replied "yes."

"We have tried and tested approaches to defend our bases around the country and throughout the world," he told reporters.

Speculation about the motives behind the incident ranged from terror threat to fuel theft, as energy prices in the UK hit record highs this week.

Burnham previously said there were "strong indications that Iran played a part" in the incident, a charge rejected by Tehran.

Trump had previously rebuked British authorities for releasing the arrested men, all in their mid-20s, on bail – pending further investigation.

Iran's embassy in London said it "categorically rejects and strongly condemns" speculation that Tehran was involved.