DOUGLASVILLE, Ga. (AP) — Investigators are trying to determine what sparked a large fire that set off a chain of explosions at a propane gas business in metro Atlanta.

The blaze sent towers of flame above the trees surrounding Blossman Propane Gas in Douglasville late Thursday. News outlets report witnesses described hearing a series of explosions that shook nearby buildings.

Douglas County spokesman Rick Martin said there were no reports of injuries. He said about 20 firefighters responded to the blaze as neighboring homes and businesses were evacuated.

Early Friday police reopened nearby roads that had been closed through the night.

Martin told reporters late Thursday that fire investigators were on the scene but there was "no word on the cause."