The Guardian newspaper reported police in Ireland and Northern Ireland arrested 18- and 19-year-old men connected to a significant bomb plot. The British newspaper said police found ammonium nitrate fertilizer at their home that authorities said was meant for a car bomb.
Security officials said the discovery was "very significant," the paper reported.
The uncovered plot follows a series of security incidents in Ulster.
Dissident Colin Duffy was charged Tuesday for shooting at a police convoy in a Catholic neighborhood of Belfast in early December. Duffy joined the Irish Republican Army as a teenager. He was acquitted last year in the killing of two soldiers at a military barracks in Northern Ireland.
A splinter group of the IRA last week took credit for a bombing at a Belfast restaurant. The bomb exploded at a restaurant Friday without causing any injury.