Dissident republicans were accused of trying to bomb Belfast city centre hours before thousands of people took part in the city's annual marathon today.
The bomb, described by police as "substantial" and with the potential to kill, was left beside the marathon route during the night.
It contained three linked pipe bombs, three containers of fuel and a detonator and timer and was made safe by army bomb disposal experts after a series of controlled explosions.
The marathon went ahead as planned after the all clear was given, but competitors had to run passed a taped off area where the clearance operation was continuing.
Police said a Phoenix Gas engineer had been forced to drive the primed bomb several miles through Belfast after being lured to the north of the city by a bogus emergency call out.
Speaking at the scene of the attempted bombing in Upper Queen Street, Chief Inspector Ian Blaney said: "We are standing on the marathon route and over 7,000 participants in the marathon, a cross community event with everyone out enjoying themselves and raising thousands of pounds for charity, had to run around the taped off area.
"Had the device gone off it would have obviously disrupted the marathon." Referring to the bombers he added: "You have to ask yourself what are these persons doing for the people of Northern Ireland. What do they expect to achieve?"
Chief Insp Blaney said the Phoenix Gas employee had been lured to the Ardoyne area late last night by a caller reporting a suspected gas leak at a youth club.
When he arrived he was confronted by two masked and armed men who held a gun to his head while the bomb was loaded into his van.
He was then ordered to drive several miles to the city centre and abandon the bomb in Upper Queen Street.
Chief Insp Blaney said the bomb was a "substantial incendiary type device" which had it gone off "would have created havoc for the city centre, substantial damage and threat to the life of anyone in the vicinity."
The gas employee was distressed and terrorised, he said. "He was attending what he thought was a genuine call to assist the community in Ardoyne and was unfortunately put through this ordeal."
PA