The vehicle was targeted with a remote-controlled bomb in Shangla area of Khyber-Pakhtunkhwa province this evening.
Deputy Superintendent of Police Bahadur Khan was among the five policemen killed in the attack, DIG Abdullah Khan told the media.
The policemen were on a routine patrol when they were attacked, officials said.
No group claimed responsibility for the attack.
On Friday, seven policemen were killed when militants ambushed a convoy on the outskirts of Peshawar, the capital of Khyber-Pakhtunkhwa.