Gunfire at the Hartsfield-Jackson Atlanta International Airport on Saturday resulted from an “accidental discharge” of a firearm, officials said, but it caused holiday travelers to flee and seek cover as some believed there was a gunman inside one of the terminals.

The airport said on Twitter that there was no gunman or danger to passengers or employees, and that no one was injured. At about 1:30 p.m. on Saturday, there was an “accidental discharge” at the airport’s security screening area, the airport said.

Officials gave an “all clear” and resumed normal operations about two hours later, the airport said.

The panic occurred during one of the busiest times of the year for air travel, when millions of people are expected to fly for Thanksgiving. The Transportation Security Administration said on Wednesday that airline travel this Thanksgiving was expected to approach prepandemic levels.

The authorities did not specify how many shots were fired or who was responsible. Sgt. Jarius Daugherty, a spokesman for the Atlanta Police Department, said officers were “working to determine the circumstances surrounding” the weapon’s discharge.

The Federal Aviation Administration said all departing flights at the airport had been grounded for 35 minutes.

Some passengers shared on social media that they had to exit their departing flights to be rescreened. Videos also showed that those who had to get off the planes had to stay on the tarmac while they waited for more information.

In the moments of confusion, the airport seemed to descend into chaos. Images posted to social media showed a part of the airport emptied out, with stray suitcases, a spilled drink and a toppled cart among those things left behind.

Outside the airport, people gathered at the departures area, blocking some traffic as passengers waited for answers.

Mark Hager, an associate professor at Arizona State University, tweeted that the airport was in “pandemonium” as he drove into it.

Adriana Loya, a reporter with 12 News in Arizona, said on Twitter that no one knew where to go. Airport employees were telling passengers that there was “an active shooter” by the baggage claim in terminal T, she said.

“Just ran in a stampede out of delta terminal,” another eyewitness, Matthew Schwartz, tweeted, adding, “I heard shots and then people were running. I helped a woman get up.”

Another passenger, Amelia Swaggert, who was traveling to Atlanta said in a tweet that she “immediately heard screams” when she got off her flight.

“Everyone was running through the terminal and we’re on tarmac now,” she said.