ATLANTA – The FBI’s Atlanta field office confirmed Thursday that agents responded to the Georgia secretary of state’s office after receiving a suspicious letter. An agency spokesperson said it was part of a broader investigation into similar incidents nationwide.

The confirmation comes on the third day of early voting in the state, which has seen record turnout so far.

Last month, the Oklahoma City FBI, in coordination with the U.S. Postal Inspection Service, launched an investigation into a series of suspicious mailers sent to election officials in several states. Some of these letters contained an unknown substance.

“The FBI and the United States Postal Inspection Service are investigating a series of suspicious mailings sent to election officials in several states. Some of the letters contained an unknown substance and we are working closely with our enforcement partners. law enforcement to respond to each incident and securely collect the “We are also working with our partners to determine how many letters were sent, the person(s) responsible for those letters, and the reason for those letters,” the statement said. Oklahoma City FBI “As this is an ongoing matter, we will not comment further on the investigation, but the public can be assured that safety is our top priority. We would also like to remind everyone to exercise caution in handling mail, especially mail from unrecognized senders. If you see anything suspicious, please contact law enforcement immediately.

The FBI has not yet released details of the letter received at the Georgia Secretary of State’s office, or whether it contained any substances.

FOX 5 reached out to Sec. Brad Raffensperger’s office for comment, but have not received a response.