Passengers have been allowed to return to the evacuated area of Atlanta's Hartsfield-Jackson International Airport after an explosion early Tuesday morning.
The Atlanta Airport Twitter feed said: "There was a small electrical explosion at 8:40am near gate D21. Passengers were evacuated but have returned. No injuries reported." It also said full power has been restored and all operations have resumed.
No fire or smoke was reported after the explosion, but power was out at Concourse D, said fire department spokeswoman Janet Ward.
Airport officials could not be immediately reached for comment.
In a separate incident, authorities reported a bomb threat at a building near the Georgia State Capital in downtown Atlanta, a spokeswoman for the Department of Public Safety said. No further details were immediately available.
Hartsfield-Jackson is one of the world's busiest airports, handling more than 95 million passengers last year.