A manhunt is underway across the city after a prisoner who was out on temporary release failed to return.
The man, who is believed to be from the North Circular Road in Dublin 8, is serving a five and a half year sentence for a violent robbery of a shop, where he tied up the staff and threatened them with a knife.
The prison service has confirmed that he was released last week to attend a drug treatment course and failed to return after.
Gardai have now launched an investigation into the whereabouts of the man, who has been described as "dangerous".
More to follow.