An explosive device described as an extremely significant car bomb was seized by Gardaí in County Monaghan as it was being transported toward the border for an attack in Northern Ireland.

Members of the Garda Special Detective Unit stopped a vehicle on the N2 south of Carrickmacross at around 3pm on Wednesday, July 22. A woman in her 20s, the driver, was arrested at the scene. A man in his 40s was arrested later in Dublin. Both remain detained under Section 30 of the Offences Against the State Act.

The device was a fully constructed bomb containing military-grade explosives, a power unit and a detonator. Garda sources indicated it was intended to be used as an under-car bomb in Northern Ireland.

The arrested woman was a law student and legal textbooks were found in the vehicle.

Garda Commissioner Justin Kelly confirmed the operation was intelligence-led and said the seizure was not just components but a complete explosive device that could have caused significant damage. He said a small minority of dissident republicans who rejected the Good Friday Agreement and refused to decommission weapons continue to pose a threat.

Justice Minister Jim O'Callaghan described the find as very worrying and very significant, saying a very serious criminal act would likely have occurred had it not been intercepted. He praised the Gardaí and noted close cross-border cooperation with the PSNI.

Northern Ireland Secretary Chris Bryant thanked An Garda Síochána for quick and decisive action that saved lives. PSNI Assistant Chief Constable Davy Beck said the seizure underlined a joint commitment to tackling violent dissident republican groups.

DUP leader Gavin Robinson said the reports were chilling and raised serious questions about the Irish Government's assessment of the dissident threat. He called for relentless, intelligence-led action from both governments.

Ulster Unionist Party deputy leader Diana Armstrong expressed shock and thanked the Gardaí, saying a small and dangerous minority still sought to drag Northern Ireland backwards. She said those responsible should face the full force of the law.

Sinn Féin TD Matt Carthy called the discovery deeply concerning and said such groups had no mandate and should disband.

PSNI Chief Constable Jon Boutcher attended the Garda graduation ceremony where Commissioner Kelly addressed the media, underscoring the close security relationship.