A worker at a food-service container plant near Atlanta was shot and killed Friday morning, and the shooter was later caught in Alabama, Rockdale County Sheriff Eric Levett said.

Gunfire was reported at Dart Container Corp. in Conyers, about 25 miles east of downtown Atlanta, around 7 a.m., the company said.

"We evacuated the building and management staff are assisting law enforcement, who are securing the site. At this time, we have no further information on the victim or the shooter," Dart said.

Employees are giving statements to law enforcement off site, and the company is "working closely with the Rockdale County Sheriff's Department, the Conyers Police Department and other law enforcement agencies on the investigation," Dart said.

Levett said the suspect was later caught at a Greyhound bus station in Birmingham, Alabama.

At least three schools and the county school transportation offices were placed on lockdown, Rockdale County Public Schools said on Twitter at 8:34 a.m. ET.

"All of our students & staff are safe. No visitors are allowed on campus at this time," the tweet read.

All schools returned to normal operations later in the morning, the district said on its website.

Dart Container manufactures and distributes food-service products such as cups, plates, containers, lids and straws, at plants and centers across the country, including the Conyers plant, the company's website says.

"We have approximately 300 employees in our Conyers plant, which makes thermoformed food and beverage packaging products," Dart's statement said.

"Counseling support will be available to our Conyers employees and we will support the affected employee and family throughout this tragic event. The facility will remain closed until further notice," the company said.

People with the FBI's area field office headed to the scene to support local agencies leading law enforcement's response, a federal source with knowledge of the situation said.