MINNEAPOLIS (AP) -- A terminal at Minneapolis-St. Paul International Airport was evacuated for about four hours Wednesday as a bomb squad worked to determine the source of suspicious smells dogs detected in two machines.
Airport officials evacuated the Humphrey Terminal around 6:30 p.m. after two dogs sat down next to an ATM machine and a vending machine - signs that the highly trained dogs had detected explosives, said Pat Hogan, a spokesman for the Metropolitan Airports Commission.
The terminal was reopened around 10:20 p.m., though it wasn't immediately clear what the dogs had sensed.
''This could be something as simple as somebody lighting off fireworks during the Fourth of July, and then having residue on them and touching a machine,'' Hogan said. ''We hope it's as simple as something like that.''
About 200 passengers and employees were sent to a parking garage across the street from the terminal while the Bloomington bomb squad was sent to the scene. No one was reported injured.
Security officials said they reacted with great caution because of last week's terror bombings in London, said Jim Welna, who heads the federal Transportation Security Administration force at the airport.
The Humphrey Terminal has 10 gates compared with 117 at the much larger Lindbergh Terminal, which was not affected by the evacuation. The airfield was not disturbed either, Hogan said.
Scott Walden, who was returning a rental car to the airport after a drive from Ann Arbor, Mich., was herded into the garage along with the rest of the evacuees. He said he didn't know what was going on until police told people to stay away from windows.
''That's when I knew there was a bomb scare,'' he said.
One of the machines tipped off by the dogs was located at the south end of the terminal while the other was near the center. Wells Fargo sent technicians to open the ATM machine, Hogan said. He didn't know what, if anything, had been found in either machine.
Airport police have six trained dogs and handlers who patrol airport property.
Flights coming into the Humphrey Terminal, which handles many charter flights, were diverted to the Lindbergh Terminal. But air traffic was light as Sun Country was the only airline operating out of Humphrey on Wednesday night. At least three flights set to leave Humphrey were delayed while at least three incoming flights were diverted, Hogan said.
Torii Hunter, the Minnesota Twins centerfielder who spent the All-Star break in his native Arkansas, was on a Sun Country flight arriving from Dallas that was delayed on the tarmac. He and his wife spent more than an hour on the plane after it had landed.
''I saw people sitting down in the middle of the runway, and there were police everywhere. I said, 'Something's not right,''' Hunter said. ''I sat there praying everything was OK.''
A line of cars backed up Wednesday night along the road leading into the Humphrey Terminal. Police manning a checkpoint about a half-mile from the terminal kept cars from entering the area.
Hunter said the flight attendants on his plane did a good job of keeping the atmosphere relaxed, ''But I wasn't relaxed. ... I was scared for a minute,'' he said. ''I wanted to find out what was going on.''
After the terminal was reopened, police began letting cars back in, and most of the passengers who had been sent to the parking garage had gone home.
Riley Karbon, a recent Tartan High School graduate, was anxious to resume her family trip to San Francisco. But she wasn't complaining about the delay.
''I feel safe that they went to this extreme to make sure everything is OK,'' she said.