Police can confirm that six people have been taken to various hospitals in the area by land and air ambulance following the collision.
The road has now been reopened in both directions with an on-off diversion in place at Grimston Bar and drivers are being warned to expect delays and avoid the area if possible.
Police officers were called to the scene, near Grimston Bar, at around 1.30pm today (15 August).
Three vehicles – two cars and a commercial vehicle – are involved.
Anyone who witnessed the incident is asked to contact North Yorkshire Police's control room on 101, quoting reference number NYP-15082016-0238.