Police have released this artist's impression in the hope of identifying robbers who threatened to cut off the head of a 15-year-old boy.

The incident happened on Sunday, May 6, when a group of friends were sitting on the beach behind the Kingsway 303 pub near Basin Road South, Hove, at about 11.15pm.

They were approached by four men aged 18 to 20 and between 5ft 5in and 6ft tall.

One man, with a skinhead haircut, headbutted a 15-year-old boy and placed a knife to the victim's ear.

He said: "Don't try to move or you'll lose your head."

A gold ring with a square diamond was taken from the boy's hand while a second victim was headbutted and held on the ground with a baseball bat.

It is believed another of the men was also carrying a knife.

The four made off on foot towards Brighton.

Anyone with information should contact Detective Constable Graham Mepham, of Hove CID, on 0845 60 70 999.