Four people have been killed after Delhi-Dibrugarh Rajdhani Express derailed near Chhapra in Bihar early on Wednesday morning.br br According to reports, 11 coaches of train number 12236 have derailed.br br Railways, while confirming the death of 4 people in the accident, has not ruled out sabotage in view of a shutdown call by Maoists in the area.br br Relief and rescue operations are on in full swing at the accident site. Relief train is taking the stranded passengers to the nearest station.