A true martyr

Just read this story on CNN. I consider Aitazaz Hassan Bangash a true Martyr, one who sacrifice himself protecting others.
Question remains as why the suicide bomber targeting school children, which would be prohibited by Quran. I have read Quran that Muslims should not kill people unless in self defense or another condition (can't remember what it is but it should not apply to school children). If the guy behind the attack is Muslim, can he/she still be considered a Muslim after violation of the Quran?

(CNN) -- A 14-year-old boy is being hailed as a hero in Pakistan for tackling a suicide bomber -- dying at the main gate of his school and saving schoolmates gathered for their morning assembly.

Ninth-grader Aitazaz Hassan Bangash was on his way to the Ibrahimzai School on Monday in the Hangu district of northern Khyber Pakhtunkhwa province when the bomber, dressed in a school uniform, asked him where the school was, the teen's cousin told CNN.
Aitazaz and his cousin, Musadiq Ali Bangash, became suspicious, Musadiq said.
"The other students backed off, but Aitazaz challenged the bomber and tried to catch him. During the scuffle, the bomber panicked and detonated his bomb," he said.
Rajab Ali, who also witnessed the bombing, told CNN that he saw Aitazaz throw a large stone at a boy trying to enter the school. The blast happened when Aitazaz grabbed him, he said.
Aitazaz and the bomber died at the scene. Witnesses say the blast injured two other people.








Iftikhar Ahmed, a Hangu district police officer, confirmed the details of the attack to CNN.