A 13-year-old boy was arraigned on a weapons charge after police say his younger brother showed up at school with a gun.

The teenager has been charged with criminal possession of a firearm after his 8-year-old brother allegedly brought this loaded .380 caliber handgun to P.S. 91 in East Flatbush Friday morning. No shots were fired and no one was hurt.

Union officials believe the boy brought the gun to school because of an ongoing fight with another student.

The Department of Education called the circumstances troubling and it is working with the NYPD to investigate. The father of the two boys was questioned by police and released.