A man was taken to hospital with severe concussion after he was kicked in the head during a robbery.
The victim was repeatedly kicked in the head and face until he let go of his mobile phone.
He was taken to the Royal Sussex County Hospital, Brighton, and later released.
The attack happened in Palmeira Square, Hove, on Tuesday at 8.15pm but details have just been released.
The victim, a 32-year-old man from Hove, was walking ahead of a gang of four teenagers, including a girl, who were being rowdy.
He told police that they surrounded him and he was punched and kicked to the ground, where the attack continued until he let go of his phone.
PC Justin Burtenshaw said: "This was a violent robbery.
"At that time of night the area would have been quite busy and we would like to hear from any witnesses."
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