Sarwar Hussaini, spokesman for the provincial police headquarters says that the explosive materials were attached to a bicycle that was parked close to the police head quarters.
He said that one policeman and nine civilians were wounded in the explosion.
Hussaini added that initial investigation suggests that the explosive materials might have been detonated through a remote control from a far distance.
Victims have been transported to the hospital where one civilian is reported to be in critical condition.
No group has claimed responsibility for the explosion.