Updated

A bomb threat temporarily cleared out San Antonio International Airport on Wednesday after officials said someone called alleging that three packages had been left inside a parking garage.

About 2,000 passengers in the terminal were herded onto the tarmac for about 1½ hours after the unknown person called around 2:30 p.m. warning about the packages, and flights were not allowed to land at the airport, fire and airport officials said.

No suspicious items were found in an intensive search aided by bomb-sniffing dogs, airport spokesman Rich Johnson said. He said the "all clear" was declared about 5 p.m., allowing flights to resume and roads leading to and from the airport to reopen.

"The K-9s (initially) had hits in the garage. But they have not found any devices. Sometimes they get false positives," San Antonio Fire Department spokeswoman Deborah Foster said.

The investigation is ongoing.

Passengers taken out of the terminal were later funneled onto more than two dozen city buses, each able to carry about 36 people, VIA Metropolitan Transit spokeswoman Priscilla Ingle said.

Kristen Reeves, a Chicago hotel marketing representative, said she was returning home when she was evacuated from the terminal.

"They took us outside, and we were out in the sun for a while," she said. "I was standing in the security line and I heard the security personnel say, 'Lockdown!' really loud."

Another passenger, Scott Holcomb, 34, of Tulsa, Okla., said the evacuation was well-organized and that water was provided to evacuees standing in the hot sun. He said that after about 20 minutes, they were led to a shaded area and then eventually were able to return to the building.

He said most people were calm during the evacuation.

"This is just one more of the big inconveniences of travel," said Holcomb, who was rebooked on a later flight back to Tulsa.