A massive explosion at a chemical plant in Georgia caused a huge plume of smoke, and authorities have instructed residents and businesses to shelter in place.

People in the northern part of Rockdale County were ordered to evacuate and others were told to shelter in place with windows and doors closed.

Thousands of people were evacuated Sunday when a chemical plant fire sent a large, hazardous plume of smoke into the air about 30 miles east of Atlanta. It's unclear when residents can return home.