The Minister for Foreign Affairs, Mr Brian Cowen, has condemned this morning’s attack at the BBC studios in London.
Mr Cowen said it was the "mindless act of people who have rejected all attempts to bring peace to these islands and who have no alternative to offer except misery and grief".
Meanwhile, Scotland Yard refused to say today whether the high explosives used in the car bomb was Semtex.
But if it emerges the bomb did contain Semtex, it will only heighten unionist concerns about the access of dissident republicans to Provisional IRA arms dumps.
Ulster Unionist leader David Trimble warned today there was already evidence that dissident groups like the Real IRA and Continuity IRA have got their hands on Provisional IRA material.
He told BBC Radio 4's ‘Broadcasting House' programme: "One of the great worries about this situation is that it would seem that on the ground it is difficult to tell the difference between the Real IRA and the mainstream IRA.
"There is evidence of material and expertise which has leaked from the mainstream IRA to those who are engaged in these incidents. That was clearly demonstrated with an under car booby trap bomb which, again thankfully, did not succeed in causing any fatalities.
"But it clearly involved and included material which came from mainstream IRA arms dumps which is why we continue to press for those dumps to be put out of use permanently and in a way that it could never be used again."
Additional reporting PA
