Middlebury school officials say a bullet found in hallway of Memorial Middle School caused the school to go into a lockdown Friday.

Students were told to shelter in place.

Once police finished their search, students were released from their classrooms and dismissed.

Police say the bullet was a single unspent 9mm round.

Police also confirmed no additional rounds or weapons were found in the building.

In a letter to families, Principal Jennifer Murphy thanked students and staff for their patience during the lockdown.

Anyone with information on the incident is asked to contact the school.