An investigation is underway after a gun and silencer were found in a van in Dublin on Wednesday.
Armed gardaí fired a number of shots when the vehicle failed to stop in Inchicore shortly before 3.00pm.
Officers seized a gun and a silencer and a man aged in his 20s was arrested at the scene.
He is being held at Ballyfermot garda station.
Another vehicle, which is believed to have been involved, fled the scene.
The Garda Ombudsman Commission has been notified of the incident.