The teen allegedly had the handgun hidden in his waistband at Notre Dame High School.
The West Division of Durham Regional Police surrounded the portable and other nearby portals were evacuated while the school was placed on lockdown after alerted about the situation around 1 p.m.
The student, 15, was arrested without incident at 3:15 p.m. A search of the portable found a Glock-style pellet gun inside the studentâ€™s gym bag.
The other students in the portable were not threatened during the incident. Reports indicate that they were unaware of the weapon.