Ten others were injured in the explosion, which is believed to have been triggered by a bomb placed in an auto rickshaw. The incident took place in Khyber Pakhtoonkhwa province's Dera Ismail Khan city.
Deputy Superintendent of police was one among those killed in the terror attack.
Among others killed were the police officer's driver, two children and a woman. The police official, Iqbal Khan, who was driving home from work, seemed to be the target.
The blast destroyed the auto richshaw and the police van.
No militant group has claimed responsibility for the attack yet.
However, over the past year, security forces and personnel have been targeted constantly by Taliban militants in the region.