The Aiken Department of Public Safety, along with the FBI South Carolina Law Enforcement Division, responded to the call in the 600 block of Washington Circle shortly after 2 p.m., Cpl. Jeremy Hembree said. The substance, which was described as being “similar to dry fire extinguisher powder,” was found on several mailboxes on Washington Circle.
Authorites tested the substance for more than five hours to determine its makeup, Hembree said. Residents were not asked to evacuate their homes, but the immediate area remained taped off.
After the substance was found to be harmless, public safety officers notified the neighborhood, Hembree said.
Authorities don’t know how the substance got on the mailboxes.
Aiken County Emergency Services and the National Guard Civil Support Team also aided the investigation.