A man has been arrested by gardaí investigating an aggravated burglary in Castleknock in Dublin.
Two men dressed as postal workers entered the house in Georgian Village just after 11am on Friday morning.
They produced a firearm and the occupants of the house were threatened.
One of the occupants managed to get out of the house during the incident.
The two men then left the scene in possession of a safe and items of jewellery.
A man is being detained under Section 4 of the Criminal Justice Act at Blanchardstown garda station.