The bomb, planted in a rickshaw, went off late Tuesday in Peshawar, killing two patrolling policemen and wounding seven others including three civilians Press TV reported.
The civilians were transferred to a local hospital.
No group has yet claimed responsibility for the attack.
The incident comes five days after a bomber on Thursday assassinated a prominent Pakistani police commander who took a leading role in anti-Taliban operations in Peshawar.
More than 35,000 Pakistanis have lost their lives in bombings and other militant attacks since 2001 when Pakistan joined an alliance with the US on the so-called war against terrorism.
Source : Afghan Voice Agency (AVA), Kabul