Provincial police chief Abdul Saboor Nusrati said the suicide bombers were looking to enter the police headquarter compound but were recognized by security forces.
He said two of the suicide bombers were shot dead while one of them detonated a vehicle packed with explosives, leaving a policeman injured.
In the meantime, Gen. Ayub Salangi, Senior deputy interior minister for security affairs, said the attack was carried out by a group of five suicide bombers.
Gen. Salangi said two of the suicide bombers were shot dead while three others detonated their explosives, leaving one person dead and three others injured.
The Taliban militants group claimed responsibility behind the incident.