The FBI characterized the threats as "credible"

By Alexis L. Loinaz
Updated January 24, 2015 04:10 PM

The FBI is investigating bomb threats made against two flights at an Atlanta airport Saturday.

According to local reports, Delta Airlines flight 1156 from Portland, Oregon, and Southwest Airlines flight 2492 from Milwaukee, Wisconsin, were being held on the tarmac at Hartsfield-Jackson International Airport shortly before 3 p.m. as authorities investigated the “credible” threats.

An airport spokesman would not elaborate on the source of the threats or how they were received, but he said that authorities “believed them to be credible,” according to the Atlanta Journal-Constitution.

The threats were later reported by Atlanta Journal Constitution to originate from a series of Tweets that a Twitter user sent to Delta and Southwest Airlines’s social media accounts. The alleged tweets have since been deleted.

Passengers from both planes were rescreened at the airport but authorities found no explosives on either planes.