A serious crash involving two vehicles has blocked the A4 at Fyfield, on the outskirts of Marlborough, causing long traffic delays.
It happened outside the Fyfield Garage and police are on the scene.
Eye witnesses say children, including a baby, had to be cut free from the wreckage by firefighters and the air ambulance was sent to the scene.
Road closure notices have been put up at the Beckhampton roundabout, on The Avenue at Avebury and the A4 near Manton.
The narrow country road between Manton and Lockeridge is clogged with traffic trying to find an alternative route.
Drivers at Lockeridge attempting to get through to Manton are having to turn round because there is no way past the line of oncoming traffic, estimated to be snaking back a mile.
Caroline Baker, of Calne Wild Bird and Animal Rescue, was caught in the tailbacks while en route to collect a cage to help with the animals the service rescues. An hour long journey took them two hours.
"I do hope those involved in the accident are OK," she said.