Specialist Garda units arrested 66 suspected terrorists in 2012, the third-highest number in the EU, after France and Britain.
The EU Terrorism Situation and Trend Report said a new republican alliance, dubbed the new IRA, was behind the murder of a prison officer in the North last year. David Black, 52, was driving to work at Maghaberry prison when he was ambushed and shot dead on the M1 motorway in Co Armagh on Nov 2.
The report, compiled by EU police agency Europol, said the group was formed through the merger of the Real IRA, Republican Action Against Drugs, and a small group of unaffiliated militants.
“This ‘new’ IRA demonstrated lethal intent and capability through the murder of a prison officer in the attack [on Mr Black],” said the report. “It is thought likely that the group will carry out further attacks.”
The report said the Continuity IRA continued to experience “internal problems and leadership struggles”, having split into separate entities. This was highlighted this month with the conviction of Limerick woman Rose Lynch for the murder of David Darcy in Dublin in Nov 2011.
Lynch, a member of the Limerick section of the CIRA, mistakenly believed Mr Darcy was a member of a rival Dublin CIRA unit.
The report said the work of security forces had resulted in significant numbers of arrests, disruptions and recovery of terrorist material.
The 66 arrests in 2012 compared to 69 in 2011, 62 in 2010, and 31 in 2009.