After 30 years of the conflict known as 'the Troubles' in Northern Ireland, it seemed by the summer of 1998 that killings and violence had at last given way to hope. Huge strides towards a political settlement had been made with the Good Friday Agreement, which had received the backing of 71% of the country in a referendum at the end of May. Elections to the new Northern Ireland Assembly had taken place in June, with a power-sharing executive to be nominated the following year. Peace finally appeared to be possible.

When a huge car bomb exploded in the market town of Omagh on a busy Saturday afternoon in August that year, the shockwaves were felt across Northern Ireland and the world. It was the single worst atrocity of a conflict many had thought was over, claiming the lives of 29 people and two unborn babies.

Threat to peace

The bomb in Omagh was not a one-off. It was the culmination of a campaign which had been building for months. In October 1997, the quartermaster of the Provisional IRA had resigned and persuaded several other key members to form what they called the 'Real IRA' to continue the "armed struggle". The split came about over the decision of the organisation's political wing, Sinn Féin, to support the fledgling peace process that eventually led to the Good Friday Agreement. Those who broke away saw it as a betrayal of the republican ideal - for the whole island of Ireland to be a united independent nation.

This new group of "dissident republicans" began planning their campaign to derail the Northern Ireland peace process almost immediately. In January 1998, security forces thwarted their attempt to detonate a car bomb in the town of Banbridge.

After attacks in Moira and Portadown, the Real IRA carried out a second attack on Banbridge on 1 August 1998. This bore many of the hallmarks that would be seen in the Omagh bombing. A large car bomb exploded in the middle of the town on a Saturday afternoon, injuring 35 people and causing millions of pounds worth of damage. A warning had been given, but the police were still clearing the streets of shoppers when the bomb went off.

Atrocity in Omagh

Saturday, 15 August 1998, was the final day of Omagh's annual carnival week. The streets were packed with shoppers taking advantage of the summer sales and buying uniforms ahead of the new school year. At 3.10pm, a massive car bomb containing 225kg of explosives detonated in a vehicle parked in the middle of Omagh's main street. A warning had been called in 40 minutes earlier, but had wrongly indicated the location of the car containing the bomb. Police had begun to evacuate the area, but were actually shepherding people towards the site of the explosion. Those who thought they had reached safety were instead caught up in the most devastating single atrocity of Northern Ireland's Troubles.

The death toll of 29 included nine children and three generations of one family. Avril Monaghan had taken her mother, Mary Grimes, on a shopping trip to celebrate her 66th birthday. With them was Avril's daughter Maura, at 18 months the youngest victim. Avril was also heavily pregnant with twins. All of those killed were civilians. They were Catholic, Protestant and Mormon, man, woman and child, ranging in age from one to 66. Over 200 people were injured, some left without limbs, others blinded or disfigured. Local priest Father Thomas Canning said: "I really don't know how the town of Omagh is ever going to come to terms with this awful catastrophe."

In the days after the attack BBC News reflected feelings of anger at the bombers' misleading warning and the raw grief of people in the town.

Political repercussions

In the immediate aftermath of the bomb, fears were high that loyalist paramilitaries would break their ceasefire and retaliate against the Real IRA. Unionists in favour of the Good Friday Agreement and those against it were driven further apart. Pressure increased on British Prime Minister Tony Blair to demand that the IRA decommission its weapons.

As Sinn Féin members in the border area between Northern Ireland and the Republic of Ireland asked disaffected colleagues to give the peace process a chance, suspicion fell on a dissident republican group called the '32 County Sovereignty Movement'.

The hunt for the killers

British Prime Minister Tony Blair said that the bombers would be "pursued to the utmost", a view supported by Irish Prime Minister Bertie Ahern who said: "We are at one as to what is required."

But despite a huge cross-border police investigation costing tens of millions of pounds, no-one has yet been criminally convicted of the bombing. Sean Hoey, an electrician from south Armagh, was acquitted of murder in 2007 with the judge in that case delivering a withering critique of the police investigation, describing it as "seemingly thoughtless and slapdash".

In 2008 Northern Ireland's former police chief, Sir Ronnie Flanagan, apologised to victims' families. In 2009, two police officers accused of lying during the trial were cleared of criminal misconduct.

Media Investigations

In 2000, the BBC's Panorama took the highly unusual step of naming suspects in its programme 'Who Bombed Omagh?'

Presenter John Ware described how the bomb was prepared, the mobile phone exchanges between the bomb car and scout car, the inadequacy of the bombers' warning calls, and how the police were misled into moving people into danger.

A second Panorama programme in 2008 called 'Omagh, What the Police Were Never Told', disclosed that the British intelligence agency GCHQ, was monitoring telephones used by some of the bombers. Detectives hunting the bombers were never told this, even though the numbers could have given them vital leads to key suspects.

Omagh families fight back

The victims' families took a landmark civil action in 2009. The judge in that case ruled that Real IRA leader Michael McKevitt along with three others - Liam Campbell, Colm Murphy and Seamus Daly - were responsible for carrying out the atrocity. The 12 relatives of victims who took the action were awarded more than £1.6m in damages. As of August 2013, they have not recovered any money from those found to have been responsible.

Appeals

The four men subsequently launched appeals. Michael McKevitt and Liam Campbell failed to have the judgement against them overturned.

Colm Murphy (a Dundalk based contractor and publican) and Seamus Daly (Murphy's former employee) were ordered to face a civil retrial and in March 2013 were again found liable for the atrocity.

Delivering his summing up, the judge, Mr Justice Gillen, said: "The barrier of time has not served to disguise the enormity of this crime, the wickedness of its perpetrators and the grief of those who must bear its consequences."

Colm Murphy and Seamus Daly have appealed the ruling. Their case will be heard in November 2013.