Five terrorist suspects arrested near the Sellafield nuclear waste site in Cumbria, have been taken to Carlisle, Manchester for questioning.

The men, all in their twenties and from London, were detained at 4.32 pm on Monday afternoon under section 41 of the Terrorism Act, following a stop-and-search check on a vehicle by officers from the Civil Nuclear Constabulary. The constabulary polices the Sellafield site in north-west England.

The North West Counter Terrorism Unit is leading the investigation.

The arrests came within hours of news of the killing of Osama bin Laden by US forces. But Greater Manchester police said on Tuesday: “At this stage we are not aware of any connection to recent events in Pakistan.” They added that there was nothing to suggest that Sellafield was immediately under threat.

There are unconfirmed reports that the five men were of Bangladeshi origin. Police did not comment on the nationalities of those arrested, and they also refused to explain what had aroused the suspicions of the Civil Nuclear police, prompting them to carry out the spot check.

The Sellafield site, on the relatively isolated west Cumbrian coast, is responsible for decommissioning and reprocessing nuclear waste and for fuel manufacturing on behalf of the Nuclear Decommissioning Authority.

Measuring 6 sq kilometres, the site is the base for more than one thousand nuclear facilities including the Magnox and Thorp reprocessing plants, the Sellafield MOX plant and a range of nuclear waste treatment facilities. It has been operational since the 1940s.

The Civil Nuclear Constabulary protect civil nuclear licenced sites and safeguard nuclear materials.