LONDON, Sept 30 (Reuters) - A suspected plot against a British airbase used by US forces to strike Iran was thwarted when police were called by one of the same men later arrested at the site, The Times newspaper said on Wednesday.

The report added to intrigue surrounding events on Sunday near RAF Fairford in west England where five British men in their 20s were arrested on suspected terrorism and explosive offences.

The five, who all live in London, were released on bail even though US President Donald Trump said they had planned "big damage" and his Secretary of State Marco Rubio pointed at "a foreign actor".

According to The Times report, one of the men called emergency services shortly before being arrested in the early hours.

"Whether it was surveillance, a 'dry run' to test security or a stunt to send a message to the British government are all under consideration," The Times said, adding that investigators were unsure whether he got cold feet or it was part of a plan.

The newspaper did not cite its sources.

Police did not immediately respond to a request for comment.

One person familiar with the situation has said an Iranian-linked motive is considered the most likely, although a Russian sabotage operation or an Islamist plot were also possibilities.

Iran has denied any involvement.

Police said on Tuesday that petrol was found in the vans used by the men but no improvised explosive device.

(Reporting by Sarah Young; Editing by Andrew Cawthorne)