Peshawar city and opened indiscriminate fire on them, in one of the most gruesome attacks in recent years against children.
A group of 8-10 suicide attackers wearing paramilitary Frontier Corps uniforms entered Army Public School on Warsak Road and started indiscriminate firing, killing more than people, including 84 students, Khyber-Pakhtunkhwa Chief Minister Pervez Khattak told reporters.
20 bodies were in the Lady Reading Hospital (LRH) and 60 in Combined Military Hospital (CMH), he said.
30 injured have been shifted to LRH and 39 to CMH.
Khattak said at least one militant blew himself up inside the school building, 2-3 militants have been killed and 5-6 militants are still inside the complex.
Khattak announced a three-day of mourning.
Prime Minister Nawaz Sharif condemned the attack and termed it a "national tragedy." He has left for Peshawar to personally monitor the operation.
A police official said that the school has been cordoned off, with a rescue operation in progress. About 500 students and teachers were believed to be inside at the time of attack.
Mushtaq Ghani, provincial information minister, said the militants entered through a graveyard which is adjacent to the school, called Army Public School.
The school is close to Saint Mary High School located at the start of Warsak Road which was also under threat for last couple of days.
A heavy contingent of police and security forces have blocked the roads leading to the school, taking control of the entire area.
In a brief statement, the army said: "Rescue operation by troops underway. Exchange of fire continues. Bulk of student and staff evacuated. Reports of some children and teachers killed by terrorist."
The Tehreek-e-Taliban Pakistan spokesman claimed that its six suicide bombers attacked army school.