A girl of about 14 used a knife to threaten a group of teenage girls.

She had already struck out with her fists at the three in Tilgate Park, Crawley.

The final stages of the Prom in the Park music festival were taking place nearby.

The girls were walking near the lake just after 11pm when the girl lashed out.

One of the injured girls had a black eye and the other two were slightly bruised.

The attacker was slim, with collar-length straight brown hair. She was wearing large hooped ear-rings, a short black skirt, and a dark top.