One day after shots were fired outside a south Fulton County high school and two schools were placed on lockdown, Union City police announced a fourth arrest in connection with the incident.

Channel 2 Action news is reporting two juveniles have been charged with disorderly conduct and two young adults face reckless conduct and firearms-related charges.

“We are not releasing names or photos due to (the) ongoing investigation,” police told Channel 2.

Investigators believe an argument between students led to shots being fired in a Banneker High School parking lot Tuesday shortly after noon, a school district spokeswoman said.

“Shots were fired in the parking lot, into the air,” Susan Hale, Fulton County Schools spokesman, said outside the school.

Investigators believe multiple people were present when shots were fired, but it was not known how many could face charges for the incident. The names of those arrested were not released.

No one was injured, but both the high and nearby Feldwood Elementary were temporarily placed on lockdown, according to Hale.

“We don’t believe, at this point, that the weapon was inside the school,” Hale said.

Investigators believe between two and five people were involved in the altercation, which is being investigated by both Union City and school system police. Parents at both schools were alerted to the incidents, Hale said.

Just before 2 p.m., authorities swarmed an apartment complex off Buffington Road looking for others who may have been involved, Channel 2 Action News reported.

Around 2:30 p.m., Feldwood Elementary students were preparing for dismissal per their normal schedule, Hale said. Banneker remained under a soft lockdown, meaning all outside doors were locked, but students and teachers were allowed to move freely in the building, she said.

One mother told The Atlanta Journal-Constitution one of her children sent her a text about the shooting. But when Katina Singleton went to the school, she wasn’t allowed to pick up her three teenagers early.

“I would prefer to take my children home,” Singleton said. “I would feel safer if they could come home. You hear shooting, and you think about Columbine.”

High school students were later dismissed after the lockdown was lifted.

— Staff writer Michelle E. Shaw contributed to this report.