By Toby Shepheard and Will Russell

FAIRFORD, England, Sept 29 (Reuters) - US Secretary of State Marco Rubio said the "hands of a foreign actor" were involved in an incident in which five men were arrested on suspected explosives and terrorism offences near a ‌British airbase used by US forces to strike Iran.

British police declared a major incident at the RAF Fairfordbase in western ‌England following the arrests early on Sunday, and the government held a national emergency meeting.

However the police released the five on bail on Monday, but said the investigation was ​not over and they were examining whether individuals acting for a foreign state were involved.

A source familiar with the situation told Reuters that three large white vans the men appeared to travel in had not contained viable explosives.

The source said Sunday's police response had not been intelligence-led - an i...