An investigation has been launched after a man was seriously injured on the Phibsborough Road in Dublin.
The assault happened shortly after 7pm on Monday.
The victim, who is in 40s, suffered head injuries in the attack and was taken to the Mater Hospital. He has since been transferred to Beaumont Hospital, where he is in a critical condition.
Gardaí are appealing to anyone who was in the Phibsborough Road area between 6pm and 7pm that night and who may have witnessed the assault to come forward.
Officers also want any motorists with dashcam footage, who may have passed through, to get in touch with Mountjoy Garda Station on 01 - 6668600, The Garda Confidential Line 1800 666 111 or any Garda Station.
No arrests have been made and investigations are ongoing.