The families of nine people killed in a series of bomb attacks known as Bloody Friday are set to mark the 50th anniversary of the atrocity on Thursday.
Five men, two women and two children were killed when the Provisional IRA detonated 22 bombs within 80 minutes across Belfast on July 21st, 1972.
Two soldiers, Stephen Cooper (19) and Philip Price (27) and four Ulsterbus workers — Jackie Gibson (45) Thomas Killops (39), William Irvine (18), and William Crothers (15) were killed at Oxford Street bus station.
Margaret O’Hare (34), Brigid Murray (65) and Stephen Parker (14) died in an explosion close to shops on the Cavehill Road.
No one has ever been convicted of the attacks.
[ Bloody Friday bombings: Fifty years on and mark of trauma has not fadedOpens in new window ]
The Provisional IRA issued an apology in 2002, and said it had not been their intention to kill “non combatants”.
Kenny Donaldson, of the victims group the South East Fermanagh Foundation (SEFF), has been supporting several of the families of those killed. He said they deserve accountability.
Mr Donaldson described the day 50 years ago as Belfast being “literally on fire”.
“On that fateful day, the Provisional IRA detonated 22 bombs robbing the community of nine citizens, from 14 years old through to 65, Protestant and Catholic, they were murdered in a day of sheer terror,” he said.
“The purposes of the Provisional IRA’s actions that day was to destabilise Northern Ireland and our capital city of Belfast, they sought to instil fear and breed division.”
Mr Donaldson said the families of those killed “have never received focus or resources lavished upon them”.
“They have carried on with a quiet yet steely determination,” he said.
“A number are connected with SEFF and we hope that in the forthcoming weeks and as a result of the additional focus there has been upon this milestone anniversary that others will identify themselves to us, and we will want to provide practical support and assistance to them,” Mr Donaldson said.
“Bloody Friday was a brutal premeditated day of co-ordinated violence. No one has been held accountable for it. We are clear that this is unacceptable, the families deserve accountability, their loved one’s lives mattered.
“Today we also think of all those who were injured and also those who provided the emergency response following the attack.”
Commenting on the anniversary, the Taoiseach said: “Today marks the fiftieth anniversary of one of the most appalling days in what was a year of tragic and terrible events across Northern Ireland.
“On a busy Friday afternoon, nine people were killed in a shocking and mindless act of terror. They died following the explosion of multiple bombs by the Provisional IRA within moments of each other in the centre of Belfast. A further 130 people were seriously injured and countless others traumatised.
“I want to express my profound sympathy today with all of their relatives and with the survivors from that devastating afternoon of violence. Together across the island, we should take a moment to remember those who lost their lives and who were brutally injured. It is also a time to reflect on the journey we have come on since those dark days and the importance of reconciliation as we look to the future on this island,” Micheál Martin said. — additional reporting PA