A man has died following a fatal assault in the Shancastle area of west Dublin early this morning.
Emergency services were called to the scene at about 5.50am.
A man in his 30s was found unresponsive.
He was brought to John Connolly Hospital Blanchardstown but was later pronounced dead.
Another man in his 30s was arrested in connection with the investigation and is being held at a garda station in Dublin.
The scene is currently preserved for forensic examination.
The coroner and the Office of the State Pathologist have been notified and a post-mortem examination will be arranged in due course.
A Senior Investigating Officer has been appointed and an incident room has been established at Lucan Garda Station.
A Family Liaison Officer will be assigned to support the family of the deceased man.
GardaĆ have appealed to anyone who may have witnessed the incident to come forward.
They are also appealing to anyone with camera footage, including motorists with dashcam footage from the area between 5am and 6am this morning, to contact them.
Anyone with information is asked to contact Lucan Garda station on (01) 666 7300, the Garda Confidential Line on 1800 666 111, or any garda station.