Published Thursday, 12 September 2013
Twenty-nine people, including a woman pregnant with twins, were killed when the Real IRA bomb ripped through the Co Tyrone market town on 15 August, 1998.
A statement from Secretary of State for Northern Ireland Theresa Villiers on Thursday said that she does not believe there are grounds for a new inquiry.
She said: "I do not believe that there are sufficient grounds to justify a further review or inquiry above and beyond those that have already taken place or are ongoing."
Victims and relatives said they were not surprised, but that they are bitterly disappointed.
Michael Gallagher, whose 21-year-old son Aidan lost his life, told UTV: "The decision certainly didn't surprise us but some of the issues she raised in her response are quite disappointing."
Families have called for a full public inquiry to be launched into what was one of the darkest days of the Troubles, when a massive 500lb car-bomb detonated among shoppers.
Last month they released details of an independent report they had which alleged there had been intelligence failings in the lead up to the bombing.
They said the document, compiled by London-based security experts, includes emails detailing communication between an FBI agent who had infiltrated the Real IRA at the time of the bombing, and his handlers.
They claim the messages identify Omagh as a potential target and establish a time frame consistent with the eventual attack.
However Ms Villiers, in her statement, continued: "I believe that the ongoing investigation by the Office of the Police Ombudsman for Northern Ireland is the best way to address any outstanding issues relating to the police investigation into the Omagh attack.
"The fact remains that the Real IRA carried out the bombing in Omagh on 15 August 1998, murdering 29 people and injuring many more. Responsibility is theirs alone.
"Representations received by the Secretary of State showed there was support for an inquiry among a number of survivors and families of those killed in the bomb, but others felt that a further inquiry would cause them considerable trauma."
Mr Gallagher continued: "At least now we know that we really have to go to the courts.
"We will judicially review the decision that the Secretary of State has taken, we will put the evidence that we have before the court and we will let them decide."
No-one has ever been criminally convicted over the bombing.
Four republicans were found liable and ordered to pay £1.6m compensation in 2009 in a landmark civil case taken by some of the bereaved families.
Ms Villiers offered to meet the Omagh Support and Self Help Group to explain her decision.
© UTV News