According to police, explosive material was planted in three classrooms of the school which went off with a loud noise.
The attack also left the school’s watchman injured. He was immediately shifted to a local hospital where his condition was reported as out of danger.
As a result of the blasts, three rooms of the school were badly damaged.
Following the explosion, police cordoned off the area and a search operation went underway.
Hangu borders the northwestern tribal region of Orakzai, one of Pakistan’s seven lawless districts on the Afghan border considered to be the hub of Taliban and Al Qaeda-linked militants.