The three active republican terrorist groups are:
Oglaigh na hEireann (also known as "Real IRA")
Formed last year by a group opposed to the Gerry Adams/Martin McGuinness leadership and the decision to call a second and most likely permanent Provisional IRA ceasefire. The group initially consisted of 30 to 50 members mainly based in the Newry/Dundalk area, with some support in north Dublin.
The group emerged at the same time as the formation of the Sinn Fein ginger group calling itself the 32 County Sovereignty Movement, which is also largely based in the Dundalk area. Garda sources say the group is the political wing of the "Real IRA", although it denies this. The "Real IRA" recruited several dozen disaffected ex-IRA members from Dublin, including Ronan MacLochlainn, who was shot dead by gardai while attempting to rob a security van in Co Wicklow in May.
Security sources estimate present membership at between 100 and 200. It has access to Provisional IRA explosives and detonators and some of its members were former leading IRA bomb-makers. It has no support in nationalist areas of Derry or Belfast.
Continuity Army Council IRA (also known as Continuity IRA)
The Continuity Army Council IRA was set up as the paramilitary wing of the splinter political party, Republican Sinn Fein (RSF), which split from Sinn Fein in 1986. The "continuity" in the group's title derives from the RSF belief that it is the true inheritor of the original IRA's mission. It regards the Dail as an illegal assembly.
The CACIRA carried out some car bomb attacks in Co Fermanagh but has apparently declined largely due to Garda attention in the past year. It may have had only a few dozen members and appears to have been overtaken by the "Real IRA" as the group most likely to succeed the Provisional IRA.
Ex-IRA members tend to avoid contact with the CAC group as they see them as too amateurish. Its main support base appears to be between south Donegal and north Leitrim.
Irish National Liberation Army (INLA)
Despite almost two decades of internal feuding and a history of ex-members becoming involved with organised crime and drug trafficking, the INLA has managed to exist as a small, hardcore terrorist group. It has a history of extreme acts of violence and it tends to recruit highly-dangerous young men from poor working-class Catholic backgrounds.
Its doctrine includes the view of the extreme Leftist groups of the 1970s that acts of extreme violence can "radicalise" the working classes. It shot dead loyalist Billy Wright in the Maze Prison at the New Year, sparking off a spate of loyalist violence in which 12 Catholics were killed.
Some leading INLA figures have recently indicated they would like a ceasefire, mainly to win early release for the 30 or so prisoners held in the Maze and Portlaoise. However, other members oppose this.