Emergency services were called to reports of a man having been assaulted in Brighton Road, East Worthing at around 2.55pm today (Friday, March 31).
He was taken to hospital for treatment to facial injuries.
Enquiries are ongoing to establish the exact circumstances of what happened and identify and locate any suspects.
Anyone who witnessed anything suspicious in the area is asked to contact police online or via 101, quoting serial 819 of 31/03.