Pine Bluff Police Chief Kelvin Sergeant said investigators believe the shooter is a 15-year-old man who is also a student at Watson Chapel Junior High.
The suspect was located near the school, hidden behind a house.
He was taken into custody and is currently being held at the juvenile justice center in Pine Bluff, authorities said. No formal charges have yet been filed.
There is no known motive for the shooting, said Sergeant, calling it an isolated incident. The school followed the active gunman’s protocol, Sergeant said.
In a Facebook post, the school system said students were safe and schools were shut down.
Pine Bluff is located about 45 miles south of Little Rock, the state capital.
Correction: This story has been updated with the correct age of the victim. The victim is 15 years old.