Thirteen persons have been arrested in connection to the incident which took place yesterday in Bidoli village of the district, Deputy Superintendent of Police C P Singh said.
The clash broke out when members of the sand mafia gang fired upon locals after they confronted them over the illegal sand mining being carried out on their land near the river Yamuna, Singh said.
Village head Anwar Shah was injured in the clash. The mafia also allegedly attacked some local journalists when they went there to cover the incident, he added.
A case has been registered against 100 persons, of whom 19 have been named, Singh said, adding that JC machines, tractor trollies and equipment being used by the mafia gang has been impounded.
Meanwhile, security in the area has been tightened and extra police force have been deployed to prevent any outbreak of violence.