M15 failed to tell police about Omagh bombing tip-off

MI5 withheld vital anti-terrorism intelligence just months before the Omagh bombing, it emerged yesterday.

Even after the explosion, which killed 29 people, MI5 failed to inform Special Branch of the threat, and details have only just emerged as part of an investigation into an FBI agent who infiltrated the Real IRA, the dissident republican group which carried out the attack.

Relatives of some of the Omagh dead yesterday said they were astonished by the disclosure, and with MI5 preparing next year to take control of national security intelligence in Northern Ireland, one MP called on Downing Street to abandon its plan.