ATLANTA (AP) — Georgia election officials acted quickly earlier this month to thwart an attempt to flood the state's absentee voter portal in an apparent attempt to crash the site, the secretary of state's office said.

The attack was limited to that part of the state's website, which voters use to request an absentee ballot. Users may have experienced a brief slowdown, but the site never crashed and no data was compromised, said Gabriel Sterling, a top official at the agency.

He said it was not clear where the attack originated. There has been no public indication that similar systems in any other state were subject to the same kind of attack.

The Georgia secretary of state's office alerted federal authorities about the attack. The FBI, the federal Cybersecurity and Infrastructure Security Agency and the Office of the Director of National Intelligence all declined to comment Thursday.

Detection tools that the secretary of state's office has in place generated an alert about a processing slowdown shortly after 5 p.m. on Oct. 14, the day before early in-person voting was to start. Sterling said internet security firm Cloudflare sent an indication within minutes that it was a denial-of-service attack, which involves flooding a site with data in order to overwhelm it and knock it offline.

The secretary of state's office could see that, at the peak, at least 420,000 IP addresses were trying to access the site at the same time, Sterling said. The office put in place a verification tool requiring users to prove that they're human and then the traffic "just sort of fell through the floor," Sterling said. Within 30 minutes of the first alert, he said everything was back to normal.

Cloudflare told Georgia officials that many of the IP addresses had been used in previous denial-of-service attacks.

"In general, our systems worked," Sterling said. "We just executed. There was not panic at all."