Emergency services were scrambled to Billund airport in Denmark on Saturday following a bomb threat.
Danish Police confirmed the incident, without divulging further details, but urged people to stay away from the site.
Scores of firefight vehicles were seen rushing to the airport, the second largest in Denmark, a witness told Danish TV 2.
While the terminal was evacuated, other passengers were first stranded in the planes before being taken to an old terminal building, local media reported.
Meanwhile, planes en route to the airport were rerouted, TV 2 reported.
By 1 p.m. local time (11 a.m. GMT), no official information was available regarding the incident, but TV 2 published footage of a man in handcuffs being led away from the airport by police.
Around 4 million passengers passed through the airport last year, Radio Denmark reported.
