London - The British government will re-examine all the intelligence information available to the authorities in the immediate run-up to the worst single terrorist atrocity in Northern Ireland, the Omagh bombing of 1998.

Prime Minister Gordon Brown ordering the review Wednesday following claims in a BBC television documentary that British intelligence had tapped the mobile phones of the attackers minutes before the massive bomb exploded, killing 29 people, including a woman pregnant with twins.

The attack, on August 15, 1998, was the worst single atrocity in Northern Ireland's 30 years of terrorism and civil unrest.

No-one has been jailed for the bombing, for which the Real IRA - a dissident group within the former Irish Republican Army, claimed responsibility.

According to the BBC's investigative Panorama programme, British intelligence monitored the perpetrators' phones on the day of the attack, suggesting that it could have been prevented.

The exchanges heard on the tapes include the phrase "the bricks are in the wall," believed to have been a coded reference to the 227-kilogram-bomb having been planted, the BBC report said.

Ray White, a former deputy police chief in Northern Ireland, told Panorama that it would have been "manna from heaven" if the intelligence information had been passed on to local forces in Northern Ireland without delay.

Arrests could have been made in the "golden hours" after the attack when forensic and other "evidential opportunities" were at their maximum.

The attack in Omagh, a small market town in the west of Northern Ireland, came only months after the political parties in the province had signed the Good Friday Peace agreement in Belfast.

Brown said the review would be carried out by Peter Gibson, the Intelligence Services Commissioner, and will be completed within 3 months. (dpa)