But, writes our correspondent, the breach represents the most serious and most public rift within the organisation's ranks for well over a decade.
At least two key members of the IRA leadership are reported to have quit the organisation in a disagreement over the Irish peace process, it was confirmed last night.
Security and political sources were playing down the significance, pointing out that the dissidents have no apparent intention of linking up with other republican factions such as the Continuity IRA.
None the less, it poses fundamental questions about the control which Gerry Adams, Martin McGuinness and their supporters exercise over the republican movement as a whole. Observers will be watching anxiously for any signs within the IRA or Sinn Fein of wider dissatisfaction with the peace process.
The doubts grew last night when a dozen members of Sinn Fein in the Co Louth area of the Republic walked out of a meeting announcing their resignation from the party. Such public disagreements are highly unusual within republicanism.
At the moment there is no indication that this parting of the ways is anything but peaceful. Republicans speak of those who have resigned as "stepping back" rather than defecting to other groups, or planning to set up in opposition. But, in the past, so many republican disagreements have led to violent feuding that everyone will be watching for any return to the gun.
While the current security assessment is that Mr Adams and Mr McGuinness remain firmly in command of the movement, those who have departed were undoubtedly central figures within the IRA. One is a Co Monaghan man who is believed to have been chief-of-staff of the organisation for more than a decade. He reportedly relinquished that position about a year ago but remained a member of the seven-strong army council.
The second dissident, while not a member of the army council, held the key post of quartermaster-general with responsibility for the IRA's weaponry.
He and his girlfriend are both said to have stepped down from the army executive, a background committee which oversees decisions of the army council. Security sources say claims that anywhere between 20 and 200 IRA activists have resigned are wildly exaggerated.
Security sources suspect, however, that there may have been a lower-level leakage of IRA material to the Continuity IRA, which has carried out several bombing attacks in recent months.
In at least one of these the bombers used Semtex, a plastic explosive which has in the past been the almost exclusive preserve of the IRA. The speculation is that someone in the IRA has been unofficially passing it on to the Continuity IRA.
The resignations are believed to have taken place at a recent important IRA meeting in Donegal, which one source characterised as a meeting called by the republican leadership to deal with dissent in the ranks.
Much of the criticism is said to have crystallised around the action of Sinn Fein leaders in announcing their acceptance of the so-called Mitchell principles. These commit participants in the Stormont multi-party talks to the use of exclusively peaceful means as well as "the total disarmament of all paramilitary organisations". Signing up was a pre-requisite for Sinn Fein's entry into talks but it may have proved the last straw for the dissidents.
The last major split in the movement dates back to 1986, when more militant elements broke away to form a party known as Republican Sinn Fein. Ever since then the Adams-McGuinness leadership has gone to great lengths to avoid splits in the organisation, and to bring their entire grouping along in the peace process, which in republican terms has always been a highly sensitive undertaking.
Irish government sources said they were not unduly alarmed about the resignations, pointing out that the ceasefire seemed secure and that the dissidents had not linked up with any other group.
Bertie Ahern, the Taoiseach, said he was bound to be concerned about any difficulties which might jeopardise the peace process, adding: "But we are talking about a relatively small number of people. We should focus our efforts on the talks. People should understand that if we are to have any political progress and peace on this island the `armed struggle' plays no part in that."
But former Taoiseach John Bruton said the development was "very worrying".Reuse content