The assault happened at around 7.30pm, on Cockburn Street, in the city centre.

The 18-year-old victim was walking with a friend on the east side of the street, close to the Scotsman lounge, when a woman approached them.

An argument took place, and the woman left only to return shortly after with a group of four men, who assaulted the victim.

He was punched twice in the face, and was taken to Edinburgh Royal Infirmary for treatment. He was then taken to St John's Hospital in Livingston, where he underwent surgery for a broken jaw.

The woman who was involved in the incident is described as white, 18 years, 5ft 3ins tall, with a large build and dirty shoulder length blonde hair. She wore a red hooded top, and had an English accent.

One of the men is described as 5ft 5ins tall, with a skinny build and dirty blond hair.

A police spokesman said: 'The victim suffered serious injuries as a result of this assault, and we are keen to speak to anyone with information that could lead us to those responsible.

'We are sure Cockburn Street would have been quite busy at this time of night, so we are confident that there will be witnesses.

'Anyone who witnessed the assault, or who recognises the descriptions of the suspects, should contact police immediately.'

Anyone with information can contact Lothian and Borders Police on 0131 311 3131, or Crimestoppers in confidence and complete anonymity on 0800 555 111.