Business operations resumed as normal Monday at the country’s busiest airport after law enforcement officials determined that there were no bombs found on two aircrafts there.

The Associated Press noted that Reese McCranie, a spokesperson for Hartsfield-Jackson Atlanta International Airport, said officials did not find bombs on Southwest Airlines Flight 2492 and Delta Airlines Flight 1156.

The Southwest flight, which arrived in Atlanta from Milwaukee and the Delta flight, which arrived from Portland, Oregon, were each taken to designated areas after they landed and searched by K-9 units.

WXIA reported that bomb threats were made via Twitter over the weekend from a user with the handle "King Zortic." That account has since been suspended, but the FBI is working to track down who sent the threats.

Per Twitter’s privacy policy, the identity of the perpetrator can be disclosed to authorities in certain emergency cases.

"We will definitely go back and track down the twitter feeds," said FBI Special Agent Britt Johnson.

Southwest Airlines released a statement and said that the safety of their customers and employees is a top priority. The airliner declined to comment on any security issue.