Military jets sent to accompany Delta planes after Twitter bomb threats

Two US airline flights accompanied by military fighter jets landed safely on Saturday at Hartsfield-Jackson International Airport in Atlanta after bomb threats were made against them, an airport spokesman said.

The threats against Delta Air Lines flight 1156, coming from Portland, Oregon, and Southwest Airlines flight 2492, from Milwaukee, were deemed credible, said airport spokesman Reese McCranie.

No bomb was found aboard the Delta flight while the Southwest flight was still being searched by explosives units, Federal Bureau of Investigation spokesman Special Agent Stephen Emmett said.

Atlanta's WSB-TV News reported that the threats were made on Twitter Inc, without citing a source.

Neither the FBI, which is leading the investigation, nor the airport confirmed the source of the threats.

Passengers from both flights were safely removed from the aircraft, McCranie said.

The aircraft were each accompanied by a pair of North American Aerospace Defense Command fighter planes as they landed at the airport, said NORAD spokesman Preston Schlachter.

^{A police officer walks on the edge of the tarmac at Atlanta International Airport (AP)}

The planes were scrambled from McEntire Joint National Guard Base in South Carolina, he said.

Southwest said in a statement that 86 passengers were aboard its flight, and that they were being rescreened.

Delta did not immediately respond to requests for comment.