School officials in Pittsburgh say a kindergartener was found with a handgun on a school bus.

Pittsburgh Public Schools spokeswoman Ebony Pugh says the gun was found in the student's backpack Monday after school was dismissed. The student attends the Pittsburgh Faison K-5 school.

Pugh says another student alerted the bus driver to the weapon, and the gun was removed without incident. She says parents were notified via the district's phone system.

Starting Tuesday, Pugh says all students will be required to pass through the school's metal detectors. Previously, only adult visitors and parents were required to do so.

Pugh says school police are investigating how the student came to possess the gun. She said in an email that "information related to specific charges" wasn't available.