A gang of up to 30 men attacked the 17-year-old driver after his Nissan Bluebird collided with a 15-year-old female member of the group on Remembrance Drive.

The enraged mob dragged the driver from the vehicle, punching and kicking him in the head and ribs until police arrived just before 5pm.

The bruised and battered driver was placed into the back of the police 4WD to protect him from the onslaught but the rampaging gang smashed the two back windows of the police vehicle and tried to drag the driver out again. Other members of the group continued smashing up the Nissan Bluebird.

"It was a mini-riot and for quite a few minutes it was out of control," Sergeant Greg Smith from Picton Police said.

"There were 30 young men full of testosterone and just three officers so it was a very volatile situation.

"We believe it was a genuine accident and the driver was not at fault but we think there may have been some bad blood between him and some members of the gang."

The driver suffered shock and bruised ribs from the incident while the 15-year-old girl struck by the vehicle was taken to Liverpool Hospital with abrasions to her back and forehead.

A 17-year-old was arrested at the scene. Police investigations are continuing.