Martin McGuinness has come under fire for telling an Oxford Union debate that he did not agree with condemnations of the IRA using a civilian worker as a 'human bomb' to murder five soldiers.
The Deputy First Minister also told the gathering that the IRA could "have killed thousands" on the streets of London and in Northern Ireland during the Troubles, if it had wanted, but that it had never deliberately targeted civilians.
He said he did not agree with the view of Bishop Edward Daly that a bomb which killed Patsy Gillespie and five soldiers in 1990 was "the work of Satan".
The event in Oxford was sponsored by Al Jazeera, the Qatar-based satellite TV channel. When Mr McGuinness made the comments about the IRA, Mehdi Hasan, the presenter, broke in to say "You're saying: 'Well, we are not al-Qaida, so give us a break'."
Mr McGuinness was repeatedly pressed on an October 1990 attack in which Patsy Gillespie, a civilian cook in a Londonderry Army base, was strapped into a van loaded with explosives. His family were held hostage and he was forced to drive to Coshquin checkpoint on the Donegal border where the bomb was detonated by remote control. He died along with five soldiers.
Bishop Daly was quoted as describing the atrocity as "the work of Satan." Mr McGuinness responded: "I don't agree with that view."
Asked if it was "anything other than cold-blooded murder", he hedged, saying: "Obviously, people will have their own interpretations of that."
At the time of the attack both the RUC and Garda were claiming that Mr McGuinness was the IRA's officer commanding, though he says he left the organisation in the 1970s.
Mr McGuinness told the debate he didn't know who was involved in the attack and couldn't discover their identities now.
Mr McGuinness also used the debate to call for a public inquiry into the Omagh bombing and information to be presented on the Disappeared.
Last night Alex Attwood of the SDLP said "no one will believe he doesn't know" who killed Patsy Gillespie. He added: "Martin McGuinness has for years been portrayed as a republican leader reaching out to others. Last night the fuller character of Martin McGuinness was on display."
Turning to the killing of civilians, Mr Attwood said: "The IRA killed nearly as many people than in the entire Irish War of Independence. The scale of the IRA terror, killings and bombings was immense, yet Martin McGuinness seems to want us to thank him and the IRA that it was not even greater."
He accused Mr McGuinness of failing to "acknowledge and face up to it that the majority of those who the IRA killed were civilians".
Victor Barker, whose 12-year-old son James was killed in the Omagh bombing in 1998 by the Real IRA, said: "I would have more respect for Martin McGuinness if he completed his democratic journey and admitted some of the crimes which he has been part of."