"I will not send my son to school. The life of my son is more important than education," says Sumaira Mahfooz, with tears streaming down her face. Mahfooz, a teacher at the Army Public School for Girls in Pakistan's city of Peshawar, lost one of her sons, 14-year old Ahmad Elahi, when his school was attacked by gunmen on Tuesday.The attackers, from the Taliban, killed 142 people, mostly students, during their nine-hour siege. They shot at children preparing to graduate from the school and reportedly burnt a female teacher alive. The attack, the Tehreek-e-Taliban Pakistan group claimed, was "revenge" for the army's six-month long anti-militant operations in the North Waziristan tribal area. Mahfooz says she does not want to return to her school, where she was when a colleague told her about the attack, and would warn other parents to keep their children at home. "I thought it would be a normal attack and Pakistan Army officials would control it and I stayed at my college," she says. It was after an hour, when reports of casualties began emerging, that Mahfooz began to worry. "I was scared and asked a male colleague to make arrangements as I wanted to go to the scene of the attack as my two sons Ahmad and Mohammad studied there," she says. "I reached near to the school on a motorbike and heard severe firing and blasts."She received a phone call from her younger son, who she found on the ground opposite the school building. They waited two hours for Ahmad before she was advised to go to the Combined Military Hospital, where many of the injured, and dead, were being sent. "There was no name of my son among the injured. Then I asked him to show me the list of those who were killed," she says. "My son's name was at the end of the list. As he called out the names, my heart was going down and down, and suddenly he called the name of my son. "I don't know what happened after that," she says. Tahira Qazi was the school's principal. When the Taliban gunmen attacked she sacrificed her life attempting to protect the children. Qazi's body was found after a long search. Her family was initially unable to pick her out from among the dead, eventually finding her when her jewellery was recognized. The mother of four, who hails from a military family, was awarded "Best Principal" in 2012.According to security officials, she had been whisked away unhurt but went back in, insisting she could not leave the children alone. "We didn't even know how secretly she went back to protect the children, while not knowing that this time she wouldn't come out alive," said the officials. Her body was laid to rest in her ancestral village, Muhallah Qazyan Landi Arbab. One of Qazi's students, Mehran, said they were gathered in the school auditorium hall when they first heard gunshots. "We became nervous and asked the teacher what had happened and we were told 'don't worry it's the sound of mirror smashing' and the teacher closed the door," says Mehran. "But within no time a young man appeared in the hall. He banged the door and started spraying bullets at children. I also received a bullet in my arm. I ran as fast as I could but I received another bullet in my back and fell in a heap on the grass. "Things started reeling in front of my eyes and I lost consciousness. I don't remember what happened to me after that, however when I opened my eyes I was in the hospital," he says. He broke into tears and said he will avenge the loss of his friends when he grows up. He said he will never forgive the Taliban. Another injured student, Irfanullah, said that his female teacher Afshaan Ahmed, 24, resisted the militants and told the students to run for their life. "The militants, in searing anger, sprinkled petrol over her and set her on fire, alive. She didn't implore the terrorists to spare the children rather she stood in their way and told them that she will not let them kill the children for as long as she is alive because I cannot see my child-like students killed before my eyes," he says. "It's an instance of true love and a greatest sacrifice. She was not only our teacher but our guard-mother as well." "I feel I am a self-centered guy because instead of being with her to save her life I ran away, I was also wounded," he said. After the Pakistani army cleared the school, they took journalists and civil society activists inside, where a candle-light vigil was held. The government has tried to react. They have lifted a de facto ban on the death penalty for those found guilty of terrorism and Prime Minister Nawaz Sharif issued several statements vowing to crush the Taliban. Karachi police claimed to have arrested two people suspected of planning the attacks, while the army renewed its air strikes against militants in the northwestern tribal region, killing 57 on Wednesday.