A student was arrested Wednesday after a school safety officer discovered a gun inside a Bronx school, according to police.

The 20-year-old student was arrested around 10 a.m. after police say a gun was found hidden inside a plastic bag at the Providing Urban Learners Success In Education High School on East 179th Street.

A school safety officer first found the .38 mm semi-automatic pistol inside a plastic bag after picking the bag up and noticing it was heavy.

Police say there were four bullets inside a magazine and none in the chamber.

The school does not have metal detectors.

A spokesperson for the Department of Education commented by saying, "The NYPD immediately responded to this serious incident, and we are working in close partnership with them as they conduct an investigation. The weapon was swiftly and safely confiscated, and all students and staff remained safe. Nothing is more important than the safety of every school building and there is zero tolerance for weapons of any kind inside schools."