Sorry guys, I missed this one!
These strange sounds occured in Lituania around 2 months ago (7th August 2012) in Klaipeda.
These strange sounds were recorded at 10:18 am just as the loud metalic bangs started. The recorder had heard about this strange sound phenomena before, but he thought they were all fakes. Now he believes in them as we all do. A nice record of these strange booms!