Authorities temporarily placed PSJA Memorial High School on lockdown after a suspicious package was found inside a boy's restroom.
Alamo police said the package was recovered and neutralized by the McAllen Police Department bomb squad.
Investigators told Action 4 News that all students and teachers were removed from the main building and rushed to the gym.
Alamo Police Chief Arturo Espinosa told Action 4 News that classes were dismissed early.
PSJA ISD administrators followed with a statement saying that buses will run early and that parents can pick up their children at the north side of the campus on Alamo road between the marquee and the "M".
Administrators added that parents need to follow the rules, so students are released in an orderly and safe fashion.
Students were released from class around 1:30 p.m. Thursday.
Alamo police told Action 4 News they will be reviewing all of the surveillance video in hopes of identifying the suspect.