The Guthrie Police Department said a grenade was found Thursday, on school property, in the backpack of a student at Guthrie Jr. High School.
The device was described to be a military rifle practice grenade.
According to police, the grenade was found by an administrator.
The Oklahoma Highway Patrol Bomb Squad responded to the school and took possession of the grenade. It was removed from the property and populated areas for public safety, police said.
Police said the administrator told authorities he believed the grenade was inert and non-functioning.
No additional details were released. News 9 is working to gather more information.