The victims, belonging to the same family from the Upper Kohistan area, were on their way back from attending a wedding function, Anadolu Agency reported.
According to Geo News, a local broadcaster, the ill-fated bus was carrying 35 passengers, including women and children, when the accident happened near the Kandia area of Kohistan.
Upper Kohistan is a hilly area bordering the Gilgit-Baltistan region.
In continuing rescue operations, locals along with specialized teams initially faced difficulties due to the darkness.
Deadly road accidents are common in Pakistan mainly due to poor infrastructure, reckless driving, and lax safety standards.