At about 5 am today, four cyclists entered the Øresund Bridge tunnel in an attempt to cross over to Sweden, reported the Danish Road Directorate on Twitter.
Traffic in both directions had to be closed for safety reasons.
All cyclists have been arrested and charged with traffic offenses, according to Copenhagen Police.
No details on their identities have been released.
Both the road and the rail link have since been reopened and are in full operation again.