The A303 westbound carriageway has been closed near Thruxton following reports of a collision involving multiple vehicles.
Police and emergency services are currently at the scene of the incident, which has resulted in the closure of the westbound carriageway between the junctions for Quarley and Weyhill, at Hundred Acre Roundabout.
Motorists are being urged to avoid the area and seek alternative routes while emergency crews respond to the collision.
In a statement, police said: “We and our emergency service partners are currently in attendance following reports of a multiple-vehicle road traffic collision on the A303, westbound carriageway, near to Thruxton.”
Officers have asked drivers to remain patient while emergency services deal with the incident and work towards reopening the road.
The number of vehicles involved and whether anyone has been injured have not yet been confirmed.
There is currently no indication of when the westbound carriageway will reopen.
Police have said they will provide further updates as soon as possible.
This is a developing incident. Love Andover will provide further information as it becomes available.