In a separate incident, a further two suspects were detained after traffic police stopped their car near the border with Northern Ireland and discovered a firearm and two pipe bombs in the vehicle, according to the news outlet.
The detainees are suspected of having links to the paramilitary groups the Continuity Irish Republican Army and the Real Irish Republican Army, both blacklisted as terrorist organizations in Ireland and in the United Kingdom.
Prince Charles and the Duchess of Cornwall will go to Ireland next week on a four-day official visit to County Sligo, visiting the area where Charles’s uncle, Lord Mountbatten, was killed in a bomb blast on his boat in 1979. The Irish Republican Army claimed responsibility for the bombing at the time.
The Prince’s trip will mark his first official visit to Ireland in 13 years.