A minor scuffle between a passenger and the conductor of a bus snowballed into a clash yesterday and their supporters pelted stones at each other.
The two groups today confronted again and indulged in brick-batting in which 20 persons, including a policeman, were injured, Superintendent of Police Abdul Hameed said.
They also targeted Siddhaur police outpost, he said.
The injured have been admitted to a hospital and police personnel deployed in the area, he said.