Dillon Heinanan leads his mom, Michelle, and brother David out of the airport during a bomb threat at San Antonio International in Texas on Wednesday. Two thousand people were herded out of the terminals and arriving flights were prevented from landing. (Tom Reel/San Antonio Express-News/Associated Press)

Passengers inside the terminal were herded onto the tarmac and arriving flights weren't allowed to land for more than two hours after a bomb threat was phoned in to San Antonio International Airport in Texas on Wednesday.

"It was three packages in a parking garage," San Antonio Fire Department spokeswoman Deborah Foster said of the phone call to the airport, which was placed some time before 2:35 p.m. local time.

The call resulted in an order to evacuate the airport, whereupon about 2,000 passengers were brought out onto the tarmac while arriving planes stayed parked away from the gates and dozens of firefighters combed buildings searching for explosives.

To get them out of the heat, passengers were later funnelled onto more than two dozen city buses, said Priscilla Ingle, spokeswoman for the area's public transit. She said the buses were staying parked at the airport but would have deployed to shelters if need be.

Bomb-sniffing dogs continue to search the parkade, but passengers have been allowed back inside the airport's terminals and flights have resumed landing as of about 5 p.m. CT.

Airport spokeswoman Nora Castro said the dogs at one point appeared to detect something suspicious in the garage, but it turned out to be a false hit. Foster said they haven't found any device. She added, though, that roads leading to and from the airport remain closed.