Incidents of stone throwing occurred in Bidar city when a protest against the murder of a schoolgirl in a village in Bhalki taluk, suddenly turned violent on Tuesday.
The police resorted to lathi charge to restore order.
The Hindu Hitharakshana Vedike had called for a Bidar bandh.
Bidar MP Bhagawant Khuba of the BJP was mildly injured in the lathi charge. One of the stones hit District Superintendent of Police D Devaraj in the shoulder.
Over 25 others were also hurt. Police vehicles were damaged in stone-throwing. The situation is now back to normal, the police said.
Khuba demanded a judicial inquiry into the lathi charge and submitted a memorandum to the deputy commissioner.
Vishwa Hindu Parishad, Bajrang Dal, Sri Rama Sena, ABVP and district Savita Samaja had supported the bandh. All shops and business establishments in the city remained closed since morning.
"We had not given permission for the procession to enter old Bidar city, which has a larger Muslim population," said police sources.