Gardaí investigating an alleged plot by an extreme right wing group to attack Galway Mosque, with threats to target migrants in other settings across the Republic, are seeking a number of suspects.

While two men appeared in court last Friday to face explosives charges, detectives believe at least two other suspects were present in Co Laois last week. They are also investigating if those men were aided by others in the Republic and Northern Ireland.

A major inquiry is now under way to determine how long the alleged plot was in the planning and what role others may have played. This could include financing, introducing suspects to each other and aiding them with expertise or in the sourcing of materials.

One of the men already charged is from Northern Ireland while the other is a foreign national living in Co Louth. After a phone was seized, as the men were arrested in Portlaoise late last Tuesday night, a video was found on it.

Right-wing extremist terror group planned destruction of Galway Mosque, court hearsOpens in new window ]

Judge Andrew Cody said in Portlaoise District Court last Friday it was a “practice” video for another that the extreme right wing group was intending to release after an attack on Galway Mosque. A group was named in the video and gardaí are working to identity its core membership.

Four men appeared in the video, all dressed in black, wearing balaclavas and with a tricolour draped in the background, Judge Cody said. He said two of the men took off their balaclavas before the recording ended and that a third had his balaclava loosely fitted around his eyes.

The Special Detective Unit, which investigates terrorism and threats to the State, is now working to identify all four men in the video and to profile them and their recent activities and who they have been in contact with.

The group named in the video, and which intended to take responsibility for the planned Galway Mosque attack referenced, was not named in court. Gardaí have identified a number of men allegedly involved with that group, with the ongoing investigation likely to continue for months, sources said.

Gardaí also anticipate further arrests in the case and two addresses, in particular, in the Republic of Ireland have emerged as locations of interest.

At last Friday’s court hearing, when two suspects were charged with explosives offences, Judge Andrew Cody remarked that the video, shown to him after the court was cleared, stated “anyone interfering would be a target” for the group.

“They say that this will not be their last attack,” Judge Cody said of the men speaking in the video about the planned Galway Mosque attack. “They describe their philosophy as an eye for an eye. They say they intend to target IPAS [asylum] centres, mosques and hotels housing migrants and that they would take this as far as necessary to achieve their goals and call on others to join them.”

A document, described as a “manifesto” for the extremist right-wing group, also forms part of the evidence, having been found during searches.

It is alleged the two men arrested last Tuesday night had in their possession four threaded pipe end caps and six litres of hydrogen peroxide, with both facing one explosives-related charge arising from that alleged discovery by the Garda.

A second charge, also explosives-related, alleges one of the men possessed at his home in Co Down “the components of three pipe-bomb-type improvised explosive devices” and “four incendiary-type improvised explosive devices”.