Police in western Germany are investigating a possible bloody conflict between drug dealers after an explosion in front of a commercial building in central Dusseldorf in the early hours of Thursday morning. Links between the blast and previous explosions in Cologne, Engelskirchen and Duisburg and an armed hostage stand-off last Friday in the Rodenkirchen district of Cologne are being investigated, prosecutors in Dusseldorf and the Cologne police announced on Thursday. The Cologne police have taken over the investigation. Nobody was injured by the detonation in Dusseldorf, but there was conside…