The five youths punched and kicked a car as it waited at a red light in Saughtonhall Drive, luring out their 23-year-old victim who had been travelling home with family after a night out.

They then launched a vicious attack, punching and kicking him before running off and leaving him lying in the road in a pool of blood. The man's 19-year-old girlfriend, who was driving his Renault Clio with her parents in the back seat, could only watch in horror as the attack unfolded.

The victim, who is from Livingston, was rushed to Edinburgh Royal Infirmary with serious facial injuries and later found to have suffered a fractured cheekbone.

Police today said they believe the teenagers – said to be aged between 14 and 18 – had ambushed the car at 12.15am on Saturday as they were "spoiling for a fight".

Sergeant Mike Leask, who is leading the inquiry from Corstorphine police station, said: "The victim was punched and kicked in the head while he was unable to defend himself.

"It was a completely unprovoked attack by a group who acted like a pack of wolves.

"The car had stopped at the lights at the junction with Corstorphine Road when this group kicked the car. Understandably, this man got out to try and stop them causing further damage to the vehicle.

"The family were left very distressed at what they witnessed happening and were unable to get out the car to offer any help as the assault took place so quickly. These teenagers behaved like savages then ran away. It seems likely they kicked the car in an effort to get a reaction because they were looking for trouble.

"The victim and his family stay in the Livingston area and were returning home after a night-out in the city"

Doctors at the ERI treated his wounds but were able to discharge him later the same day after deciding plastic surgery would not be necessary.

The area near to Saughtonhall Drive was the subject of a police crackdown on antisocial behaviour in recent months which saw homemade weapons, including socks stuffed with snooker balls, seized from teenagers. Several youths were arrested in connection with offences such as possession of drugs during the blitz. centred in locations around the Saughton Sports Complex.

A hardcore of around 20 youths from the Saughton, Stenhouse and Chesser areas were involved in the disturbances. The police blitz was hailed a success after the number of calls from local residents fell dramatically.

Police, who have stressed Saturday's attack is an isolated incident, say there "no suggestion at present" that the same groups of teenagers were involved. CCTV footage is now being scoured.

Local councillor Paul Edie said: "I absolutely condemn this attack and I would urge anyone who might know who was involved to contact police as soon as possible to help catch those responsible.

"There have been problems in the area in recent months, with antisocial behaviour involving youths and that was subject to extra patrols by police. but this incident is in a completely different order of magnitude to kids being a pain."

Pc Laura Welsh, from Corstorphine police station, said: "Security camera footage is being collected from the area in an effort to identify the attackers."

The youths are described as being male, between 14 and 18-years-old, all slim and wearing dark-coloured clothing. One had blond, spiky hair.