A gang of four punched a 16-year-old supermarket worker and stole cash from his friend.

The victims were leaving the Sainsbury's supermarket in West Green, Crawley, around 9.30pm on Saturday when four youths approached them in the car park.

They demanded the 16-year-old's mobile phone, then punched and searched him but stole nothing.

They then turned their attention to the 15-year-old and one opened his jacket to show him a knife. He gave them a small amount of money.

The youth who punched the older boy, who is also thought to have had the knife, was aged 15-17, slim and had bleached, crew-cut hair. He wore a black leather jacket, tracksuit bottoms and Nike trainers.

The offender who asked for the mobile phone was stocky, 16 or 17 and wore a dirty white baseball cap, leather jacket, grey jumper and black jeans. He had a northern accent.

Another gang member was Asian, 6ft tall, 16 to 17 and wore a black baseball cap, yellow jacket and dark trousers.

One member of the group tried to stop the crime. He was Asian, 17 or 18, 6ft tall, stocky and had a goatee beard. He wore a blue baseball cap, blue jacket and black jeans.