Worthing seafront has been closed by police as emergency services respond to an incident.
Part of Marine Parade has been closed outside the Marks and Spencer store while Sussex Police and the air ambulance respond to an incident.
The road has been closed from The Steyne down to the Royal Arcade in both directions.
A spokesman for the Kent, Surrey and Sussex Air Ambulance confirmed the service had been called at 3.15pm.
An eyewitness from the scene has reported a person having been knocked from a motorbike and taken away in an ambulance at around 4.30pm.
Sussex Police and the South East Coast Ambulance Service have been approached for more information.