A jailor was attacked by inmates in Jamkhandi of Bagalkot district on Sunday night.
V.D. Kumbar's hand was fractured. Jail staff shifted him to hospital.
Members of a gang arrested from Mahalingpur attacked him when he tried to stop them from fighting among themselves.
Accused Zakir Hussein, Fayaz Makandar, Ashok Naikodi and Arfat Talikoti assaulted the jailor, the police said.
A case has been registered.