HUNTSVILLE, Ala. (AP) — Police have charged two Whitesburg Middle School students with carrying a concealed weapon after police recovered a gun inside the school Thursday morning.

Police spokesman Sgt. Mark Roberts says Whitesburg Middle School and Whitesburg Elementary were temporarily locked down while police investigated. Administrators found a gun in a boys bathroom inside the school at around 8:30 a.m. He says the gun was not loaded.

Huntsville City Schools Superintendent Ann Roy Moore says the gun was found after a grandparent sent a tip to school officials after overhearing a conversation between two students.

Roberts says the two students were boys and are currently being held at the Neaves-Davis Center for Children.

Madison County and Huntsville authorities have been responding to reports of weapons at area schools since two violent shootings occurred on two Fridays in February. On Feb. 5, 15-year-old Todd Brown was shot to death by a classmate at Discovery Middle School in Madison; on Feb. 12, three professors were shot and three other people wounded at the University of Alabama in Huntsville. A student, whose identity is being shielded because he is a juvenile, is charged in the Discovery shooting. Biology professor Amy Bishop is charged in connection with the UAH shooting.

Since then, authorities have responded to reports of weapons at Sparkman Middle School, Buckhorn High School and now Whitesburg Middle School.