THE M4 was blocked westbound near the Leigh Delamere services after a crash involving multiple vehicles.
Emergency services were at the scene.
A Wiltshire Police spokesman said: "Fortunately, we don't believe anyone has been seriously injured but the road is blocked - we are currently working hard to clear debris so a lane can be opened."
Highways England tweeted: "We have a multiple vehicle RTC, carriageway is currently blocked. Emergency vehicles are on scene. Updates to follow. Take care on approach."
UPDATE: The motorway's lanes were cleared around 6.30pm.
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