Gardaí investigating a serious assault on an elderly man in Dublin which resulted in him suffering serious head and spinal injuries have released an image of a 'Guy Fawkes' mask they believe was worn by the assailant.

Investigating officers are particularly interested in locating the mask which they believe was possibly discarded but has not been recovered.

The brutal assault occurred at approximately 2am on Saturday morning at Courtney Place in Ballybough.

The injured man, in his (70s), was taken to the Mater Hospital, where he remains in a critical condition.

Gardaí are appealing for any persons who may have witnessed the assault, or may have seen the mask or anything matching its description to contact the incident room at Mountjoy Garda Station 01-666 8600, the Garda Confidential Line 1800 666 111 or any Garda Station.