DEKALB COUNTY, Ga. — A juvenile has been taken into custody following reports of an intruder forced Stephenson High School into a level three lockdown on Tuesday.

The DeKalb County School System said resource officers responded to the school and swept the building as the students remained in their classrooms. Aerial video showed a significant police presence at and around the school as DeKalb County Police Department officers supported with traffic control.

"All students and faculty are safe," the district said in a statement just after 11 a.m.

Police officers from both departments are remaining on campus for the duration of the day. Police said the investigation is ongoing and they haven't identified the person arrested nor have they mentioned how he was connected to the lockdown.

"The school will be on a level one lockdown out of an abundance of caution and students will resume their normal schedule," the district said in a statement.

At other DeKalb County schools, a level three lockdown means all exterior doors are locked and classroom doors are immediately locked, with students going under desks or tables.

A level three lockdown is put into place in situations where there may be a threat inside the school or a threatening person at the school, with a weapon possibly involved.

Students posted videos from inside the classrooms showing officers checking the rooms.

The school district said it intends to release more information as it becomes available.

"DeKalb County School District remains committed to being transparent and informative to the DeKalb County community," the district said in a recent statement. "The investigation remains ongoing. The district will provide updates as they become available."