CLARKSVILLE, Tenn. (WKRN) — Students at a Clarksville Montgomery County school were temporarily evacuated early Thursday morning after a malfunction with their heating, ventilation, and air conditioning (HVAC) unit.

All students and staff from Northeast Middle School have returned to class just before 8 a.m. after a spokesperson with the Clarksville Montgomery County School System (CMCSS) said there was another malfunction with their HVAC unit. The fire department was called to the scene and the school district said everyone is safe.

Last week, writing utensils were reportedly shoved in the unit causing the previous malfunction, CMCSS Spokesman Anthony Johnson stated.

School resource officers are said to be on campus assisting school officials. An investigation into the recent malfunction is underway.