Seven persons were injured in the clash and their condition is stable, they said.
The incident happened last night at Savda village in Raver tehsil when members of a group sitting in a small hotel quarrelled among themselves over some issue.
The scuffle soon spiralled into a free-for-all with two groups armed with sharp-edged weapons coming face to face and pelting stones, a police officer said.
"..People gathered at Shekhpura Gandhi Chowk locality in the area and attacked each other. They torched some vehicles including a motorcycle and some kiosks," SP Jai Kumar said, adding, around 20 persons are picked up for questioning.
Kumar said that he would take a call later in the day on reducing the curfew period depending upon the situation.