"Copenhagen police have said there is a threat against all Atlasglobal's planes in Europe," a Copenhagen Airport spokesman said, as quoted by Reuters.
One airplane was prevented from taking off due to the incident. It was moved to a remote part of the airport while police carried out their investigation.
Copenhagen Airport tweeted at the time that gates C30-C39 had been closed amid a "police investigation." It later said the airport was "back to normal" and operating with minimal delays.
A spokesman for Atlasglobal told Reuters that the airline was unable to immediately provide comment. He said it will likely release a statement later on Monday.
Atlasglobal is a Turkish airline headquartered in Istanbul, which operates domestic and international passenger services and charter flights. It operated under the name Atlasjet until March 2015.