MINDEN, La. (AP) — A small explosion Wednesday at a Louisiana plant that makes black powder is under investigation.

No injuries were reported at Goex Industries LLC and all of its employees were evacuated shortly after the 7 a.m. blast, according to multiple media outlets. Estes Energetics is the parent company of Goex, which is located at Camp Minden, a Louisiana National Guard training site about 27 miles (43 kilometers) east of Shreveport, near the city of Minden in north Louisiana.

The Webster Parish Sheriff's Office confirmed the explosion and said Louisiana State Police are now in charge of the investigation.

“Currently, there is no indication of any threat to public safety, and the incident has been contained within the perimeter of the facility,” state police said in a statement.

The agency said further details would be released as they become available.

An email was sent to Goex Industries on Wednesday seeking information about what might have caused the blast.

Goex manufactures black powder, also known as gunpowder, used for sporting applications such as civil war re-enactments and flint lock firearms. It is the only U.S. manufacturer of the explosive material, according to its website.