Four men in their 20s were arrested this morning after the attempted robbery of a security van at a post office on Church Road, East Wall in Dublin.
A masked man entered the post office armed with a firearm at around 9.20am. He threatened staff and demanded money before fleeing the scene empty-handed.
It is believed a shot was fired during the incident and one member of security staff received a minor injury.
The four men were arrested on Jones Road in the East Wall area at around midday.
They are being detained under Section 30 of the Offences Against the State Act in Store Street and Mountjoy Garda stations.
Gardaí are appealing to anyone who may have seen a dark grey Nissan Micra car with an 'L' plate travelling in the area before or immediately after the incident to contact them at Store Street on 01-6668089 or the Garda Confidential Line on 1800-666-111.