According to local media reports, the Hafiz Gul Bahadur-led Ittehadul Mujahideen claimed responsibility for the blast.
Speaking to Dawn, Khyber Pakhtunkhwa Inspector General Zulfiqar Hameed confirmed the death toll and said more than 50 people were injured in the attack.
Hameed said a vehicle-borne suicide bomber initially targeted the gate of the police facility.
He added that some attackers moved towards the Counter Terrorism Department building, where they were neutralised, while around three others headed towards the Special Branch building.
Khyber Pakhtunkhwa Chief Minister Sohail Afridi has sought a detailed report on the incident.
President Asif Ali Zardari condemned the attack and expressed grief over the loss of lives.