FRANKLIN, Ohio -- Police in Franklin said a janitor at Anthony Wayne Elementary School discovered a grenade early Wednesday morning behind the school.

Officers said they blocked the area off and called in the Dayton Bomb Squad to difuse the device.

Police said they consider this incident a criminal investigation.

According to police, the person who placed the grenade at the school could face charges of inducing panic.

News Center 7 reported this story on noon on Wednesday. Police said about an hour later, the person who placed the grenade at the school came forward. Police said it was an individual they never suspected.

Police said a 6-year-old boy with no criminal intentions actually forgot about his favorite toy and left it at the school yard.

Investigators said the device was a military-issued hand grenade. They said it was a real grenade, but it was not dangerous, because the explosive part of the device had been removed.

Police feared that a prankster was responsible for leaving the grenade at the school.

According to police, the child recently visited a military museum and bought the grenade as a souvenir.