The bullet pierced his neck, said the doctors attending on the 30-year-old deputy mayor.
He was first admitted at Central Hospital of Bharat Coking Coal Limited (BCCL) and later in the afternoon doctors referred him to a hospital in Durgapur in West Bengal, a member of his family said.
The incident occurred at around 11.30 AM when Singh was alone in his room at that time, they said.
Deputy Superintendent of Police D N Banka who visited the hospital refused to comment on the incident till initial probe was completed.
Singh was elected deputy mayor last year.
