A large number of students gathered in the auditorium to receive first aid training when the attack took place.
"Most of the students received bullets in the head," said provincial information minister Mushtaq Ahmed Ghani at Lady Reading Hospital (LRH) on Wednesday.
Khyber Pakhtunkhwa Chief Minister Pervez Khattak announced compensation of Rs 5,00,000 for the kin of deceased and Rs 2,00,000 for the injured.
Three-day mourning was also announced in Khyber Pakhtunkhwa.
As many as 141 people, nearly all of them school children, were massacred when heavily armed Taliban suicide bombers stormed a school in Peshawar, firing indiscriminately, leaving another 130 injured.
The assault began after 11:45 am, the target was particularly the children of the army personnel. However, the school, located at the edge of the country's turbulent tribal belt, also enrols civilian wards.
A 15 year old boy, who survived dodging behind a bench but with bullet shots in both the legs narrated how he survived the killing of his teacher in front of his eyes.
"One of my teachers was crying, she was shot in the hand and she was crying in pain. One terrorist then walked up to her and started shooting her until she stopped making any sound. All around me, my friends were lying injured and dead," he said.