The incident happened yesterday after the train left for Ajmer when a portion of one of the wheels of a coach broke and fell off, Chief Public Relations Officer of North Western Railway, Tarun Jain said today.
He said it was a generator coach with no passenger on board.
"Staff and gateman at one station from where the train was passing through noticed the abnormality in its movement following which the train was stopped at next station Jobner," he said.
"The coach was detached from the train which left for its destination after nearly 70 minutes," he said.