A 15-year-old student allegedly brought a loaded gun onto Brooklyn school grounds during the first day of classes.

The student, who has been detained, was found with the gun at a metal detector scanning station while walking into the Brooklyn School for Career Development on Clermont Avenue, according to ABC7.

Pix11 described the weapon as a loaded .22-caliber firearm. The incident happened shortly before 10 a.m.

"This incident is deeply troubling, and we are working in close partnership with the NYPD as they conduct an investigation," the Department of Education said in a statement to ABC7. "The NYPD immediately responded and safely confiscated the weapon. Safety always comes first and there is zero tolerance for weapons of any kind in schools."

No injuries were reported.