The vehicle with more than 12 passengers on board was on its way from Garam Chashma to Chitral district when the incident took place, police said.
So far, eight bodies have been fished out of the river Chitral. Four persons are still missing, Deputy Commissioner of Chitral town Osama Warich said.
"Though the chances of the remaining missing persons are dim, we can not say that all of them had died unless we recover the bodies from the river," he said.
Rescuers and locals rushed to the spot for the rescue and relief works.