The incident occurred at the village under Purkazi police station area when the two groups confronted each other over the Imam's appointment, Superintendent of Police, City, Deepak Gupta said.
The verbal confrontation later turned into a full-fledged clash in which fire arms, sharp weapons and batons were used by both the groups, leaving nine persons injured, The SP said.
The injured have been admitted to the district hospital, Gupta said, adding a case of rioting has been registered and 20 persons, including the Imam of the mosque, have been arrested.