A suspected shipping error caused concern at a Manorville high school Tuesday after a teacher unpacking art supplies discovered a box of bullets.

The Eastport-South Manor School District said the teacher was doing a routine inventory check of a new school-year supply order from Blick Art Materials while alone in their classroom when the ammunition was found.

According to the district, the bullets were contained in a separate, sealed box within the shipment. The teacher immediately stopped unpacking and notified school administrators and security staff.

Suffolk County police were called and took possession of the box.

The district says based on a preliminary investigation, "It is clear that this was a severe packaging and shipping error made by the external vendor or distributor as the label for the smaller box was to be shipped to a sports store in Louisiana."

The district said they are going to contact the supplier in investigating how the mix-up happened and ensure it doesn't occur again.