By Cormac O’keeffe, Security Correspondent Irishexaminer.com
The man, a welder in his 40s, has no known connections with republican paramilitaries or any other type of violent extremist group.
No manifesto or campaign linked to the suspect has been located although the results of the PSNI search are not yet known.
Initial indications suggest that personal or mental health issues may be a major factor in the man鈥檚 actions, as opposed to wider political or ideological motivation.
Sources are also investigating if the man was interested in conspiratorial theories and are examining his online activities.
The suspect is linked to two incidents in the North, which happened some years ago, and three incidents in the Republic.
One of the devices was found a year or two ago in north Dublin. A second device was recovered in Castleblaney, Co Monaghan a few months ago, while the most recent incident, in Foynes, Co Limerick, was spotted last Friday.
Security sources said that while the devices were viable, they were missing certain technical expertise.
The devices were placed at commercial premises either at connection points to water supplies or at waste treatment sites.
Garda铆 do not think it is connected with Irish Water and two of the incidents are in the North.
The Garda Special Detective Unit 鈥 the force鈥檚 anti-terrorism branch 鈥 is supporting local garda investigations, coordinating all three investigations, and is liaising with the PSNI.
The Garda Cavan/Monaghan branch is taking the lead in the local investigations.
Sources said the man went to a 鈥渉uge amount of effort鈥 making the devices, travelling the country and breaking into commercial properties to plant the devices.
Sources have moved to contradict speculation that the incident at the Aughinish Alumina refinery at Foynes is connected to its Russian ownership.
Security sources said all three devices are similar and that they have been linked to the suspect.
If the devices were detonated the damage would have been 鈥渟ite-specific鈥 and not had any wider impact on water supplies, sources believe. But if someone was near it, it could have caused significant injuries.
A Garda HQ statement said: 鈥淎s part of the investigation into the discovery of a number of attempted improvised explosive devices (IEDs) in the Northeast and Southwest of the country, a male (40s) was arrested on Sunday.
鈥淗e is currently being detained under Section 30 of the Offences Against the State Act, 1939 at a Garda Station in the North Western Region.
“An Garda S铆och谩na continues to liaise with our colleagues in the PSNI in relation to this investigation.”