A teenager was taken to hospital after he was assaulted following a party that got out of control.
The 18-year-old was injured in the assault at about 10.30pm in South Street, Tarring.
Sussex Police said that inquiries were under way to identify the suspect and the force issued an appeal for witnesses and information.
Earlier, officers used a “dispersal order” under section 34 of the Anti-Social Behaviour, Crime and Policing Act 2014.
They stepped in to break up the party, in Poulters Lane, Worthing, where the numbers and behaviour had got out of hand and to disperse the crowd.
Sussex Police said: “Detectives are appealing for witnesses following an assault in Worthing.
“Officers were called to reports of a group of around 100 to 200 people causing anti-social behaviour following a party at an address in Poulters Lane, Worthing, at 8.30pm on Friday (23 February).
“Police were quickly on scene and a ‘section 34 dispersal order’ was authorised, giving officers and designated police staff the power to disperse individuals behaving in an anti-social manner.
“The party was dispersed and the area was cleared.
“Following the incident, police received a report of an 18-year-old man who was assaulted at around 10.30pm in South Street, Tarring.
“As a result of his injuries, he was taken to hospital and inquiries are ongoing to identify the suspect.
“Witnesses or anyone with any information is asked to contact Sussex Police online or call 101 quoting serial 1474 of 23/02.”
