NEW : The Pakistani Taliban claims responsibility for the blast . The suicide bomber was a teen wearing a school uniform . He detonated his explosives in front of students and teachers at an elementary school, killing more than 100 people. The bomber was either carrying the explosives in a bag or wearing a suicide vest .
NEW : The Pakistani Taliban claims responsibility for the blast . The suicide bomber was a teen wearing a school uniform . A school for the children of military recruits is located at the training facility . The bomber was either carrying the explosives in a bag or wearing a suicide vest .