COVINGTON, Ga. — Newton County sheriff's deputies arrested a 16-year-old student and were investigating after Newton High School was placed on lockdown because of threats made to staff and students Thursday morning.

Investigators interviewed two students and released one they took into custody following the lockdown at the school, located off Crowell Road, said sheriff's office spokesperson Caitlin Jett. 

The 16-year-old, who allegedly pulled a fire alarm that led to the incident, was charged with reckless conduct, disorderly conduct, disrupting public school, and transmitting false report of a fire, Jett said. 

"We are still actively investigating the incident, and as of right now, there has been no arrest for the threats made towards the students and staff," Jett said Thursday afternoon.

Students returned to class at around 11 a.m. Thursday and administrators allowed them to leave early. Sherri Partee, Newton County School System director of public information, said Newton High dismissed students early — at 12:15 p.m. — Thursday "due to the disruption."

"Parents who choose to pick their students up as car riders may enter the campus after 12:30 p.m.," Partee said Thursday.

Partee — in an earlier statement Thursday at about 10:15 a.m. — said the incident began when "Newton High School was evacuated this morning for a fire alarm."

"During the evacuation, comments were made that were a cause for concern. Law enforcement is on [the] scene investigating. Students are still outside as a precaution. At this time, no one may enter or exit the campus."

The sheriff's office also had earlier reported that the "threats were made to harm the students and staff at Newton High School."

"There is not an active shooter at Newton High School," the NCSO said in the statement. 

The school was placed on a lockdown while law enforcement officials conducted a search of the building, the sheriff's office stated. 

"Nothing is more important than the safety and security of the school’s students and staff, and we are taking these threats very seriously," the statement said.

Schools nationwide have been on heightened alert in recent weeks following the shootings at a Nashville, Tennessee, Christian elementary school March 27. A woman who used three guns she bought legally shot her way into the school building and shot and killed three 9-year-old students and three adults before police shot and killed her. 

Publisher and Editor Gabriel Stovall contributed to this report.