Police were called to Marine Parade, Worthing, on Monday (August 13) following reports of people fighting, a spokesman said.
A man, 46, was arrested at the scene on suspicion of assault, police confirmed.
A police spokesman said: “Extra police patrols will be targeting anti-social behaviour in the shelters on the seafront.
“Anti-social behaviour will not be tolerated.
“All incidents will be investigated and the perpetrator dealt with robustly.”
Anyone who was in the area and witnesses the incident, contact police online quoting reference number 669 13/08.