A teenager was left with severe head injuries after a fight broke out between two gangs at a Thorpe Park fast food outlet on Sunday, as thrill seekers enjoyed a sun-packed day at the park.

Witnesses are being sought to the serious assault which happened at the busy KFC restaurant in the grounds of the amusement park on Sunday, July 16, at about 3pm, when two separate groups of youths, aged between 17 and early 20s, were inside the eatery.

There were at least five men in each gang and the fiasco escalated when a chair was thrown from one side of the take away shop into the other gang of youths.

The injured youth was treated by medical staff on site before being taken to St Peter's Hospital where he was treated for a serous cut to the head.

The attack happened near the Tidal Wave ride at the park, which was flooded with families.

The area was temporary cordoned off for inspection.

Officers investigating the assault need to speak to further suspects about the attack and are appealing to anyone who may have been in KFC or have any information relating to the crime to contact Surrey Police.

It is believed that other offenders were Asian and one may be of Chinese appearance.

Five men were arrested in connection with the fight and have been bailed to appear back at Woking police station in October.

A Thorpe Park spokesperson said: "Thorpe Park security and medical staff were on site within minutes in line with park emergency response procedures, and order was quickly restored.

"Five individuals were detained by police in relation to the incident. No other part of the Park or guests were affected.

"The health and safety of guests is Thorpe Park's primary objective, and the park will of course co-operate fully with the authorities, as well as carrying out our own internal investigation, as to the cause of the incident."

Anyone with any information is asked to contact Surrey police on 0845 125 2222.