UPDATE: The carriageway has since reopened – however, there are some delays in the approach to Junction 17.
The M4 is closed westbound as emergency services respond to a traffic collision.
The carriageway is shut between junctions 17 (Chippenham/Cirencester) and 18 (Bath).
Wiltshire Police and other 999 crews are in attendance.
It’s not yet clear if anyone’s been seriously injured or how long the road will be closed for.
A spokesperson for National Highways wrote: “Traffic is currently stopped on the #M4 within J17 #Cirencester due to a collision.
“Wiltshire Police are currently on scene. Delays are beginning to build on approach to the incident.”