An 11-year-old Rockland elementary school student will be tried as a juvenile after allegedly bringing a BB gun onto a school bus.

The incident happened Tuesday on a school bus leaving Willow Grove Elementary School on Storrs Road in Thiells.

Police say the bus driver overheard kids talking about the gun, looked into her rearview mirror and saw a child allegedly holding the BB gun. 

Detective Richard Spatta, of the Haverstraw Police Department, says the driver immediately stopped the bus, but the boy denied having a weapon. She called her supervisor, and the gun was found moments later under a seat.

The student is being tried as a juvenile for unlawful possession of a weapon under 16.

The case will be forwarded to Rockland County Court.

School officials say they've met with each student who was riding the bus to make sure nobody felt threatened.