Part of the M4 near Bristol has been closed following a two-vehicle crash that resulted in a number of casualties.
Police were called to the eastbound carriageway between junctions 21 and 22 just after midnight on Monday morning.
Both vehicles had left the road, Avon and Somerset Police said, while National Highways reported the cars had flipped over.
The road is likely to remain closed throughout the morning rush hour and diversions are in place.
