DENVER (KDVR) — Denver Public Schools confirmed a gun was found on a student at George Washington High School on Wednesday.

A law enforcement source told FOX31 that two students were in a fight in a bathroom when one student began digging through their backpack.

The other student reported that he heard what sounded like the slide of a gun, which is used to check if a round is in the chamber, and left immediately.

The source told FOX31 that police found a gun inside the first student’s backpack.

One student who spoke with FOX31 said it happened around lunchtime. He said the school was on “secure lockdown” for around 15 or 20 minutes, with the students required to stay inside the building.

Denver Police confirmed to FOX31 that a student was arrested for investigation of a juvenile in possession of a handgun.