SELMA, Ala. (AP) — Three Alabama high school students have been arrested after investigators received an anonymous call about a loaded gun on campus.

It happened Friday at Southside High School in Dallas County. Sheriff Mike Granthum says officers put the school into lockdown and went to a specific classroom, based on the tip.

He says two students were charged after three loaded guns were found. Another student was charged in a shooting that was not related to the school. All three were being held in a juvenile detention center.

The sheriff says the person who provided the tip is a hero.