Police are searching two airliners at Atlanta's airport after "credible" bomb threats, US officials say.
Airport spokesman Reese McCranie said the threats were received against Delta and Southwest flights coming from Portland and Milwaukee respectively.
He said both planes had landed safely. Passengers were later led from the aircraft, reports say.
US fighter jets escorted the planes into the Hartsfield-Jackson International Airport, US media say.
A bomb squad and sniffer dogs are said to be involved in the police search.
The bomb threats were made online - reportedly on Twitter.