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

The attack was limited to the portion of the state’s website where voters apply for an absentee ballot. Users may have experienced a brief slowdown, but the site never crashed and no data was compromised, said Gabriel Sterling, a senior agency official.

He said it was not clear where the attack came from. There have been no public indications that similar systems in other states have fallen victim to the same type of attacks.

Georgia’s foreign minister’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 used by the State Department triggered an alert about a processing slowdown shortly after 5 p.m. on Oct. 14, a day before early in-person voting began. Sterling said internet security company Cloudflare sent an alert within minutes that it was a denial-of-service attack, flooding a website with data to overwhelm it and knock it offline.

The secretary of state’s office was able to see that at least 420,000 IP addresses were simultaneously trying to access the site at peak times, Sterling said. The bureau introduced a verification tool that required users to prove they were human, and then traffic “just plummeted,” Sterling said. Within 30 minutes of the first warning, he said everything was back to normal.

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

“Generally our systems worked,” Sterling said. “We just executed. There was no panic at all.”