(ABC NEWS) -- A 19-year-old man briefly took employees hostage at an Atlanta-area elementary school today and exchanged fire with police, resulting in hundreds of students being evacuated from the building.
No students were harmed and the suspect was taken into custody, officials said.
Police continued to investigate the car the gunman drove to the school after bomb-sniffing dogs detected explosives.
The lone suspect entered the main office at Ronald E. McNair Discovery Learning Academy in Decatur, Ga., carrying an AK-47 assault rifle and other weapons, said Chief Cedric Alexander of the Dekalb Police.
Authorities believe the man may have entered the school by closely following a person authorized to enter the building.
Once inside, he only went as far as the front office, where he held several staff members "captive," according to Chief Alexander.
The suspected gunman ordered one of the staffers to call a local television channel, ABC affiliate WSB-TV, to request that a camera crew record him "killing police," WSB reported.
Police, including U.S. marshals, entered the school and found the gunman in the office. He exchanged fire with the officers but ultimately surrendered, Alexander told reporters.
Police believe he fired a total of six rounds.
"Once we had him in custody, we secured the entire school," Alexander said.
SWAT teams were sent classroom to classroom to evacuate students, some as young as pre-kindergarten.
Authorities have yet to establish a motive or determine whether the shooter had a link to the school.
Police planned to evacuate the children through the front of the school, but the risk of a bomb in the suspect's car led them to find an alternative route. Instead, police cut a large hole in a stretch of fence behind the school and led children down an embankment. There they were placed on school buses, accounted for, and later reunited with their families at a nearby Walmart.
Parents of nearly 600 students waited in the heat for several hours before finally being united with their children. Many were grateful no one was hurt.
"It's a blessed day: All of our children are safe," said Michael L. Thurmond, interim superintendent of the Dekalb County School District.
The shooting came on just the second week of classes at the charter school.
School safety and gun control were again thrust into the national spotlight last year when Adam Lanza, 20, killed 20 students and six adult staff members at Sandy Hook Elementary School in Newtown, Conn.