The mini bus was on its way from Thakot to Battagram in Khyber-Pakhtunkhwa province when it plunged into the ravine near Kotgala village.
The dead bodies have been shifted to district headquarter hospital in Battagram.
The immediate cause of the mishap was not known.
Road accidents are common in Pakistan where hundreds are killed every year due to traffic accidents.
At least 12 people were killed in a similar incident in Pakistan-occupied Kashmir over the weekend.
Careless driving, bad roads and faulty vehicles are common causes of such accidents.