A man is in hospital with a fractured skull following an unprovoked attack in Edinburgh.
The 22-year-old was knocked to the ground during the assault on 0335 BST on Saturday outside the Standard Life building on Lothian Road.
The man was in the area with friends when a man approached the group and began to assault his victim before fleeing towards Tollcross.
The man was taken to the Edinburgh Royal Infirmary.
The attacker was white, with tattoos on both arms and he was wearing a white T-shirt.
A Lothian and Borders Police spokesman urged witnesses to come forward.
He said: "The suspect has approached a group of men who were unknown to him and carried out an unprovoked assault that has left his victim hospitalised with a serious head injury."