Five men arrested in Luton anti-terror raid
Five men have been arrested on suspicion of the commission, preparation or instigation of acts of terrorism, Scotland Yard has said.
They were arrested at separate addresses in Luton, Beds, in an "intelligence-led" operation, the Metropolitan Police added.
The men, aged between 21 and 35, are being held at a London police station.
The BBC understands there was no imminent threat to the UK, but the arrests are described as significant.
The arrests have been made under the Terrorism Act 2000 by unarmed Metropolitan Police officers assisted by Bedfordshire Police.
A statement from the Bedfordshire force said "there is no danger to the other nearby residents" and the families of those arrested have been advised to find alternative accommodation while the searches continue.
The BBC understands the arrests were made as part of a Met Police anti-terrorism operation codenamed Nimrod.
The operation in Luton is linked to searches at five addresses in the town on 2 September 2011, although they may not be the same five as those where the arrests took place on Tuesday morning.