AP/Abdul Rehman
Aitzaz Hasan, aged around 15, and his friends spotted a man wearing a suicide vest. Aitzaz confronted the bomber - who then detonated his vest.
Aitzaz's cousin told BBC that Aitzaz told fellow students "'I'm going to stop him. He is going to school to kill my friends'. He wanted to capture this suicide bomber. He wanted to stop [him]. ... He is a shahid [martyr]. A shahid of his whole nation."
Praise has been pouring in on social media for his bravery, which likely saved numerous lives since students were disembarking from school vans. Almost 2,000 students were in attendance at the time of the attack.
To get an idea of the huge respect, here's a snippet from BBC:
"There have even been calls for him to receive the army's highest honour awarded to those who have sacrificed their life for their country, though it is unclear if he would be qualified to receive it as a civilian."
The attack took place in the Hangu district, an area of northwestern Pakistan that borders one of the country's seven lawless districts on the Afghan border that serve as hubs of Taliban and Al Qaeda-linked militants.