Ten people were being questioned in the North today after police foiled a suspected international gun smuggling plot by dissident Irish republican terrorists.
One of those detained was also being questioned about the Omagh bombing in 1998 in which 29 people were slaughtered and hundreds more injured.
The arrests were made during raids across the North by 200 police officers backed by soldiers.
Eight premises were searched in parts of Armagh and Fermanagh as police looked for possible arms dumps belonging to the renegade Real IRA, which carried out the Omagh bombing.
The investigation was carried out by the Police Service of Northern Ireland’s Crime Operations branch and British security services.
Police confirmed part of the operation was aimed at disrupting a conspiracy to procure a significant quantity of arms.
Detectives from the Crime Operations branch travelled to France and were present during related searches carried out by French police, said a spokesman.
The inquiries in Europe are continuing.
Detective Chief Superintendent Norman Baxter said the investigation had been going on for several months.
Mr Baxter, the officer in charge of the Omagh bomb investigation, added: “We believe this operation has disrupted a potential major terrorist conspiracy.”