Sher Khan and Chiku Khan assaulted the jailer of Dhanbad Jail, Md Israel, when he refused to allow a visitor to see the prisoners since it was a Sunday.
The jailer broke his left shoulder when he fell down during the assault before the jail security rescued him.
Israel was admitted to a local nursing home for treatment.
Jail superintendent Sudhir Chandra Jha told newsmen that he had lodged a complaint with the Dhanbad Sadar Police Station against the duo who are relatives of a notorious criminal here.