The mishap occurred near Tingri village when the driver lost control and the vehicle fell down a nearly 400-metre deep gorge, according to police control room here.
Relief and rescue efforts were launched immediately by the police and eight bodies including that of three women and a child were rescued from the spot, it said.
Four persons who sustained injuries in the accident were rescued and rushed to a nearby hospital.
Rescue efforts are underway but it is still not clear what exactly led to the mishap, the police control room said.
Expressing concern over the recent spurt in road accidents in the state, Rawat said officials concerned must conduct random examination of vehicles plying especially in mountainous regions from time to time.