Authorities in the U.S. state of Georgia on Sunday issued evacuation orders after a chemical plant caught fire near Atlanta, sending up plumes of black smoke.

A sprinkler malfunction early in the morning caused water to react with a chemical, sparking a fire, Marian McDaniel, chief of Rockdale County Fire Rescue, told a news conference.

“Once the sprinkler head activated, it mixed with that chemical and from that, the wiring and things, caused the fire,” she said.

While officials described the fire at the plant, affiliated with the company BioLab, as small, the reaction released huge plumes of smoke, according to footage broadcast on television.

Evacuations were ordered in the area surrounding the plant while other residents were told to shelter in place and keep their windows closed and air conditioners turned off.

Multiple roads were closed. It was unclear how many people were impacted by the evacuation or shelter-in-place orders.

The plant is about 25 miles (40 kilometers) from Atlanta.

In a statement to local media, BioLab, which produces pool and spa chemicals, said there had been no injuries reported among its employees.

The federal Environmental Protection Agency was alerted to the accident, McDaniel said.