The alarm was raised just after midnight after both security staff and members of the public observed suspicious activity at the airport, which is served regularly by charter passenger flights and is Sweden's fourth-largest hub for cargo.
“Our patrols arrived just after the suspects had climbed out of one of the aircraft, which they had broken into,” Stefan Dangardt, police press officer in the Bergslagen region, told TT.
The people, four young men and two young women, have been questioned by police. They are suspected of serious theft as well as violation of public security laws, which forbid unauthorised access to sensitive areas such as airports.
Details of what they are suspected of stealing are unclear.
“This is far from terror or sabotage. It’s about youthful stupidity,” Dangardt said.
Five of the suspects were later released and one person remained under arrest. All six remain under suspicion of breaking the law.