Emergency services are at the scene of an accident outside Pyecombe Golf Club this afternoon (Sunday).
Police officers and paramedics were called at around 1.30pm to an overturned vehicle.
A Sussex Police spokesman said there are minor injuires after the accident.
According to traffic reports, a road is blocked resulting in queueing traffic on the A23 London Road Southbound from A273 (Pyecombe) to A27.
Congestion is reportedly backing up to Muddleswood.
Rail replacement buses are also reportedly being delayed between Brighton and Three Bridges and Lewes.