A Strange Noise coming from the sky in the middle of the night - What is that?

You can best begin to hear it after ( 4:00 minutes )

In the night of 10-01-2012 in Aalborg Denmark I heard a very strange sound coming from outside, I went out to see what it was and it sounds like it came from heaven and it lasted for several minutes. I recorded the sound on my camera, and it was very loud in real life, but it can not be heard so high on the recording, as it was only recorded with a tiny camera microphone

I am quite sure that it was not a mechanically sound of helicopter or airplane, or a train (there is no trains in the area) .