An Iraqi youth slashed with a broken bottle in an "extremely violent" racist attack nearly died, police say.
The 18-year-old was rushed to hospital with severe lacerations to his neck after he was attacked in Commercial Road, Portsmouth, on Saturday night.
Hampshire Police say first aid given at the scene by a passer-by almost certainly saved his life.
They want to hear from anyone who saw the incident or the attacker - a black man in his 20s.
Det Insp Chris Seymour said the Iraqi and a young Albanian friend were both spoken to and then suddenly attacked.
"This was an extremely violent incident involving a broken bottle and a belt and the 18-year-old received serious lacerations to his neck," said Det Insp Seymour.
"The Albanian was less seriously hurt. We have seized local CCTV tapes and hope that the whole incident has been captured on camera.
"This was an extremely serious incident and I believe the first aid the victim received at the scene was absolutely vital to saving his life.
"We are treating this as a racially motivated attack due to nature of what was said to the victim before he was attacked."
A 23-year-old man from Portsmouth has been arrested.