TURNER — Tripp Middle School resumed classes Wednesday after Androscoggin County Sheriff’s Office deputies responded to suspicious items reported in a hallway, the sheriff’s office said in a statement.

The items were four rounds of small-caliber ammunition. It is not clear if the presence of the items was accidental or deliberate, the statement said. Some details are being withheld and no one has been charged as the investigation is ongoing.

Maine School Administrative District 52 Assistant Superintendent Teresa Gillis notified parents and guardians via phone about the situation while the school was in a holding pattern for officers to clear the school and investigate. Administrative staff and the Sheriff’s Office later determined the school was safe to resume classes and after-school activities, though both organizations kept additional staff present out of an abundance of caution and to reassure families, the call from Gillis said.

Superintendent Cari Medd sent a letter home to families later in the day describing how the incident unfolded. A school staff member found a bullet in the stairwell in the morning and brought it to Assistant Principal Shawn Rice. Rice informed Principal Jana Mates, and both searched the surrounding area and found three additional rounds. Administrators pulled video footage to investigate and notified Medd and authorities asking for guidance.

Sheriff’s Office personnel suggested holding students in place while authorities investigated and reviewed footage. Students who were searched were only those who had an advisory or first-period class downstairs near where the ammunition was found. No one was identified via searches and video footage, though the Sheriff’s Office took video footage for detectives to review.

“We are grateful for the help and support from the Sheriff’s Office and are proud of how our students and staff responded to the situation,” Medd said in the letter.

Any information on the incident should be shared with the Sheriff’s Office at 207-753-2500 or MSAD 52 central office at 207-225-1000.