ATLANTA — The tick-tick-ticking sound of a bag alarmed employees at the world’s busiest airport, but it has turned out to be nothing more than a passenger’s toothbrush.

The battery-powered toothbrush was responsible for the sound that gave rise to fears of a bomb at Atlanta’s airport Friday morning. It led police to cordon off a section of the north terminal while a bomb squad responded.

Airport spokeswoman Myrna White says AirTran employees heard the ticking sound after the bag was dropped off shortly before 7:30 a.m. at the airline’s kiosk, near the curbs where cars and buses pull up to the north terminal. White said some travelers were diverted to the south terminal and normal operations in the area resumed by 8:10 a.m.