A man was taken to hospital with head and facial injuries after an unprovoked attack at Duke’s Mound in Brighton.
Sussex Police said: “At around 3.30am on Saturday (23 January), a man reported being struck numerous times over the head by an unknown object.
“A passer-by heard the attack and intervened and was hit in the face by the suspect, who then ran off towards Brighton Marina.
“The suspect is described as a white man in his late twenties, about 5ft 8in, with blond spiky hair. He was wearing a white t-shirt under a blue jumper, light blue jeans and white trainers.
“The first victim was taken to Royal Sussex County Hospital with head and facial injuries and the second victim sustained minor facial injuries.”