PHOENIX — Parts of the largest terminal at the Phoenix airport were closed and flights were canceled Sunday as police investigated an unattended vehicle, airport officials say.

Three of four security checkpoints of Terminal 4 at Phoenix Sky Harbor International Airport were closed for more than three hours Sunday, airport officials said.

Police said the vehicle was a rental car. Bomb-sniffing K-9s were called to the scene. Authorities were able to remove the car from the airport before noon Sunday.

PHOTO GALLERY: Unattended rental car after police cleared it

Travelers before the security checkpoint on the east side of the Terminal 4 were evacuated, said Deputy Aviation Director Julie Rodriguez.

"Any time we deal with a vehicle— that's a large object— it's different than if we had a small package or something like that," Phoenix police officer Tommy Thompson said. "That's more complex requires different methods to thoroughly search those vehicles to make sure it's safe."

Southwest Airlines canceled 34 flights, coming in and going out, and advised travelers to expect a few more cancelations. According to FlightAware, Phoenix-bound flights were delayed at their origin.

The Arizona Department of Transportation said the exit to Sky Harbor Boulevard on State Route 143 was closed.

traffic stopped at sky harbor 9-16-18
Officials partially closed Sky Harbor's terminal 4 as police search an unattended vehicle Sunday morning.
Rich Prange/ 12 News

Traffic entering the terminal was stopped Sunday morning for the incident, resulting in miles of traffic build up.

Terminal 4 airlines include Air Canada, American, British Airways, Southwest Airlines, Volaris, WestJet and Condor.

Travelers who are impacted by the delay should check for updates to their specific flights with their airline.

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