The A4361 is closed in both directions this afternoon following a road traffic collision.
It reported happened on the stretch between Wroughton and Avebury at around 4pm today, with at least two vehicles suffering serious damage — one has overturned.
Wiltshire Air Ambulance has landed at the scene, but it is not yet clear how many people have been injured. 
Motorists can expect severe delays in the area for the foreseeable future.
