Two men, aged 49 and 28, will appear before a special sitting of the Special Criminal Court charged in connection to an investigation into dissident republican activity.
Gardai arrested both men on Wednesday evening at Forgney, close to Ballymahon, Co Longford.
The arrests took place following the discovery of an improvised explosive device in a car.
The men were detained at Longford and Granard Garda Stations.
To other men, aged in their late 20s and late 40s, were also arrested and have since been released from custody. A file is being prepared for the Director of Public Prosecutions.