The group raided the man's house at Barieya village last night shortly after finding the carcass, they said.
The police rescued him from the marauding mob and admitted him to a local hospital, but later shifted him to another hospital in Dhanbad owing to the seriousness of his injuries, they said.
The man was out of danger, the police said, adding that some persons were also injured in the clash between the mob and the police. They all have been admitted to hospitals in Dhanbad.
Six persons have been detained in connection with the incident, the police said.
A case was registered at the Deori police station, Batra said.