Grand Forks International Airport was evacuated and a man is in custody after a bomb threat was made at the weekend.
Grand Forks police said Indian national Paraman Radhakrishnan allegedly made threats to airport check-in agents.
Regional Bomb Squad officers were called but no device was found.
"Police say the leading theory behind what may have caused the suspect to make these threats is that he became disgruntled with airport staff, but they say regardless of the reason any threat of this nature at an airport is taken seriously," said police spokesman Jay Middleton.
"That’s one thing that you don’t do. You don’t make reference to acts of violence, acts of threats towards staff or the facility itself. They’re trained to take the matter seriously and they’re going to respond accordingly," Middleton added.
Radhakrishnan, who was flying from Grand Forks to Minneapolis, is charged with terrorizing but could face federal charges.
