Airport spokesman Perry Cooper said a JetBlue flight from Long Beach, California, and a regional SkyWest jet from Phoenix were involved. The flights arrived yesterday afternoon.
Cooper said that out of caution, passengers were bused to their gates. He said the matter was under investigation and did not have further details.
Additionally, a Delta Air Lines spokesman said a flight from Los Angeles to Orlando was diverted to Dallas on Sunday afternoon due to "a security concern."
It was unclear if any of threats were connected. The Federal Aviation Administration didn't immediately respond to messages.
The evacuations come a day after bomb threats targeted two jets bound for Atlanta, prompting F-16 fighter jets to escort the planes.