ROMULUS, MI -- Authorities cleared travelers from 18 gates at Detroit Metro Airport as a precaution Tuesday morning as safety officials responded to a trained dog's alert on a piece of cargo.

Airport spokesman Michael Conway said Delta Air Lines customers in the McNamara terminal were moved away from the stretch of gates at 10:30 a.m.

Authorities spent over an hour investigating before determining there was no threat and reopening gates A20 to A38.

"We had a situation where a (Transportation Security Administration) canine alerted on some cargo," Conway said.

"Perhaps there was something in that cargo that had a component that the dog was trained to alert on."

He said a safety team X-rayed the item and then opened it, determining that there was nothing dangerous inside.

Operations were back to normal by noon, Conway said.

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