Authorities in Arizona are investigating a small explosion that occurred outside a Casa Grande Social Security office Friday morning, KPHO reports.

No fatalities or injuries were reported in the blast, which occurred at approximately 8:30 a.m.

AZ Family reports:

Upon arrival, police and fire officials learned that the explosion came from a device that detonated at the back door of the building, according to city spokesman Agustin Avalos. The device is unknown at this time. Fire Marshal Barbara Rice said a fire was quickly extinguished, but there was some damage to the exterior of the building.

Police say the suspect is a Hispanic man driving a black Hyundai, MyFoxPhoenix reports.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives also had representatives present, the Associated Press reports.

Nearby business were evacuated.