PARENTS are being urged to keep a closer eye on their children after a night of violence at a park in Stockton.

Thirteen police officers were called to Ropner Park after a gang of 50 or 60 youths began to cause mayhem.

During the incident a 15-year-old boy, who was walking in the park with his girlfriend, was set upon by a group of four or five youths. He suffered severe bruising after being punched and kicked and was taken to hospital for treatment.

Problems with youths causing trouble in the park have been going on for more than a few months and now police have said it has come to a head. Sergeant Colin Whitfield, the local community police officer, said: "Unfortunately, this is a frequent problem. We did manage to put a stop to it about six months ago, but it has now come back again.

"It was quite disturbing to see what they had done to the young lad. I have been convinced for a while something like this would happen.

"They do not care about what they are doing and do it because they are out of the way and can hide in the bushes when we are around."

The youths also destroyed flower beds in the incident, on Friday night, in which 30 bottles of wine and cider and 20 cans of lager were seized by police.

In a stark message to parents, Sgt Whitfield said yesterday: "If you know your child is drinking under-age you should do something to stop it.

"If you do not know where they are at the weekend you should take the trouble to find out, because they are causing misery to others."

Officers want to speak to a 16-year-old youth in connection with the assault.

He was wearing a Burberry cap, white jacket with the word Echo on the front and the number 73 on the back.

Patrols will also be stepped up in the area.

Anyone with any information about the assault or any of the damage caused is asked to contact (01642) 326326.