Further details have emerged today of the garda operation which saw five men arrested in Donegal.
It is reported in today's Irish Independent that the arrests were part of an anti-crime operation targeting dissident republican groups.
Local senior officers suspected members of a breakaway republican group were behind the intended hold-up plot in Donegal.
The splinter group, which styles itself "ONH" and is based in Strabane has been blamed for a series of crimes in the north-west in the past couple of years.
As a result of an ongoing operation by gardai against dissident republican groups in the border region, officers set up a checkpoint in Letterkenny in the early hours of yesterday.
They stopped a car and detained four suspects for questioning. An initial search of the vehicle yielded a number of items for examination, including balaclava helmets, plastic ties and an imitation firearm.
A fifth man was arrested in Buncrana.
All five can be detained without charge for up to three days.
The garda investigation into the activities of the group was stepped up last night as Special Branch officers from Dublin backed up Donegal personnel.