Garda ballistics experts were on their way to Tralee in Co Kerry last night after three Afghan asylum seekers were arrested at their hostel accommodation.
The men were being detained under the provisions of Section 30 of the Offences Against the State Act.
Under this legislation persons can be held without charge for an initial period of 48 hours.
The three men, who are all in their 30s, were arrested in a hostel in Tralee at around 5pm and brought to Tralee Garda station for questioning.
It's understood that gardaí were responding to information they had received about suspicious devices.
Gardaí recovered some wiring in a room in the hostel, which is located in the centre of Tralee.
The area was cordoned off for a forensic examination and to await the ballistics experts.
However, a senior Garda source said last night that they were awaiting the technical examination before deciding whether the wiring could have been used for any sinister purpose such as a component in an incendiary device.
"At this stage, we don't know that it was part of an incendiary device. . . we're still at a very early stage of the investigation," said the Garda source.
The men were living in an apartment within the hostel.
It is understood that two of the men had been in the country for at least a year.