The policemen were on their way to the site of an earlier explosion at Badabher on the outskirts of Peshawar when the blast occurred early this morning.
Sub-inspector Abdul Haq, in-charge of the bomb disposal unit, was among the four personnel killed by the blast near Sheikh Mohammadi area of Badabher.
Three policemen were killed instantly while another succumbed to his injuries in hospital. Their vehicle was destroyed by the explosion.
One more injured policeman is being treated in Lady Hardinge Hospital.