A 16-year-old high school was being questioned by  Chicago police Monday after a security guard discovered a loaded handgun in his backpack.

According to Chicago Public Schools spokesman Michael Vaughn, the student was entering the Bowen High School campus at 8:20 a.m. when an X-ray search of his backpack revealed the weapon.

Students at the school, at 2710 E. 89th St., are subjected to X-ray searches of their belongings every time they enter the school, Vaughn said.

A security guard who inspected the backpack discovered the gun and called police, Vaughn said.

The student fled the school, but was apprehended by police shortly afterward. He was identified by video surveillance tape and the name on his backpack, Vaughn said.

The boy is a student at New Millennium School of Health at Bowen High. No charges had been filed Monday afternoon.