SCOTLAND YARD warned at the weekend that further IRA bomb attacks in Britain may be "imminent" and may take place without any warning.
Commander John Grieve, the head of the anti terrorist squad, issued the warning after officers discover detailed documents at the London home of Mr Edward O'Brien, who was killed when his bomb accidentally exploded last Sunday. Semtex and a "substantial" amount of bomb making equipment, hidden in some garden gnomes, have also been found at his address.
Although Mr Grieve refused to discuss the nature of the documents for security reasons, it is believed they include lists of targets and individuals. Scotland Yard sources confirmed that every police force in Britain would receive a detailed intelligence dossier outlining possible IRA attacks.
Security measures for the royal family have been increased and several MPs are to have 24 hour protection. Military establishments across Britain have also been placed on "high alert".
According to the Sun newspaper, the Queen is named in the documents found at Mr O'Brien's home.
It quotes a security source as saying: "The Queen was named as the top target and Windsor Castle was one site under discussion for the launch of an attack against her."
Senior police officers fear the IRA may resort to the tactics used during the 1970s' campaign, which included the Birmingham and Guildford public house bombings, when they failed to issue any coded warnings. It is believed that London would bear the brunt of this onslaught.
The gravity of the situation will be discussed later this week at a special meeting of chief constables to assess security arrangements and update intelligence on IRA suspects.