According to rescue sources, the incident occurred due to head-on collision between bus and Hiace van, resulting in the killing of three people.
The rescue officials reached the site and shifted injured to a nearby hospital.
Punjab Chief Minister Usman Buzdar has expressed grief and sorrow over the loss of lives in a road accident that took place in DI Khan.
Earlier, on November 25, at least eight people were killed and several sustained injuries in a road accident in Dera Ismail Khan.
The incident occurred due to a head-on collision between bus and trailer.
The over speed bus was going towards Mardan from Karachi. The injured ones were shifted to the nearby hospital while further investigation is underway.