Parallels can't be drawn in terms of their brutality between IS and IRA, says father of Warrington bomb
Colin Parry's 12-year-old son was killed when a bomb exploded in Warrington in England in 1993.
He said the activities of dissident republicans bore more of a resemblance to those of Isis.
"You can't compare the IRA to Isis," he said.
"While the impact on my family and on the families of others may be the same result - the death of a loved one - there can be no comparison.
"The actions of Isis in filming their hostages and glorifying their horrific deaths are not remotely like what the IRA did.
"In terms of the brutality and the inhumanity, in slitting throats and beheadings, one can't draw a parallel.
"Their actions go beyond those of the IRA.
"Probably dissident republicans can be more equated to Isis in that mainstream republicanism is in government, while they remain committed to violence."
Mr Parry and his wife Wendy have become committed peace campaigners since the death of their son, setting up and operating a charitable reconciliation centre in Warrington. While he has said he can't forgive the IRA, he has developed a positive relationship with Deputy First Minister Martin McGuinness.
He said: "It would be hard to imagine those involved moving toward peaceful means."
He added: "When they are so embracing of death that they believe there are riches awaiting them, then it will be hard to defeat them.
"But it looked like that in Northern Ireland until there was a breakthrough found and while people will say the system it created is not perfect, but it is certainly better than what there was."