Police have called in a bomb disposal unit as a precautionary measure when a series of explosions were reported after a man died in a car fire on the M11 near Cambridge.
The southbound carriageway has been closed between junctions 13 and 12 since early on Wednesday morning.
The fire was reported near junction 12 near Barton at about 8.10am.
The M11 southbound carriageway is expected to remain closed until later on Wednesday evening
Police are appealing for witnesses as it is not clear how the fire started.
Police say there is no indication of a collision taking place or any other vehicles being involved.
Highways England is advising drivers to consider alternative routes or to delay their journey if possible. The road is likely to remain closed for most of today, possibly into the evening peak, while the vehicle is recovered and the road is repaired.
This section of the M11 is close to the interchange with the A14, which is one of the busiest routes in East Anglia.
Long delays have built up on both roads.