Gardaí step up security measures in the aftermath of Paris attacks
Gardaí have stepped up security measures at air and sea ports in the wake of the Paris terrorist atrocities.
Surveillance of targets on a garda suspect list of terrorist figures here with Middle Eastern links has also been ramped up.
There are concerns that terrorists could turn Ireland into a transit hub for extremists to travel to or from conflict zones.
Officers are closely monitoring passenger data at the ports, and are sharing updated intelligence gathered by other European police forces and agencies since last Friday night's attacks.
The measures were put in place after an intelligence assessment review that was carried out by senior anti-terrorist officers in Dublin at the weekend, and also following a briefing provided to the Government by Garda Commissioner Nóirín O'Sullivan.
Senior gardaí admit they are particularly worried at the level of co-ordination and planning involved in the Paris attacks.
"Friday night represents a step up to a more sophisticated level for these terrorists with the co-ordinated use of three teams, all heavily armed and prepared", one officer acknowledged.
"It is also significant that there was very little chatter on the airwaves in advance of the attacks and no early pointers towards the imminent shootings and bombings," he said.
One security official told the Irish Independent that while there was no specific information on a threat here, Ireland could not consider itself immune from international terrorism.
The threat level remains at moderate and was summed up yesterday by gardaí as one where "an attack is possible" but not considered likely.
However, there is concern that Ireland may become a transport hub for extremists. Focus has been placed in particular in recent months on flights between this country and the Middle East and North Africa.
There is no intelligence at this stage to indicate that any of the wanted terrorists are heading in this direction, according to officers, but contingency plans have been drawn up to seal off any possible escape routes.
Justice Minister Frances Fitzgerald said that to absolutely guarantee that attacks could never take place in a democracy would involve taking extreme measures that would change the very nature of our societies and hand ultimate victory to the terrorists.
But that did not suggest that Ireland and other countries were helpless in the face of such attacks, she added.
"The truth is that police and other agencies have prevented countless numbers of attacks by international terrorists," she said.
Gardaí also said there is no fresh evidence of an increase in the number of young people travelling from Ireland to Syria and Iraq.
Since the start of the Arab Spring, between 25 and 30 people are estimated to have gone there but not all of them are aligned with extremist groups, such as Isil or al-Qa'ida.
The involvement of such a large group of extremists in the Paris attacks has also forced EU police forces to change their views of earlier this year that the main threat in Europe is likely to be posed by individual terrorists, or "lone wolves".
One senior garda said: "If people are determined to commit atrocities, it is very difficult to stop them.
"The way forward is through the sharing of intelligence between all police forces and agencies and we are very heavily involved in that.
"At the other end of the spectrum, we also work closely with the Muslim communities in this country.
"We make it clear that we are investigating people who are terrorists, and not because they are Muslims," he said.
Garda Commissioner Ms O'Sullivan said that police liaison officers are in Irish embassies around the world.
Ms O'Sullivan added: "We keep our assessments under constant review and keep our counter-terrorism strategies commensurate with that level of threat but unfortunately it can happen any place, any time, and I think vigilance, without striking fear into the heart of the community, is really important."
Security at Northern Ireland's air and sea ports has been "hardened" following the Paris attacks, PSNI Chief Constable George Hamilton said.