The vultures were feeding on a carcass at Hakarpara railway tracks when a goods train dragged the birds, killing seven on the spot and seriously injuring four others, the sources said.
The injured birds have been shifted to the Assam State Zoo in Guwahati.
The species is found mainly in the higher regions of the Himalayas, the Pamirs, Kazakhstan and on the Tibetan Plateau, with northwestern limits of the breeding range being in Afghanistan and southern limits in Bhutan but juvenile birds may, however, disperse further south.