Three persons received bullet injuries in a clash between two groups in Mandiaon area in Lucknow, late on Tuesday night.
The injured have been admitted to a medical facility.
Three persons have been detained and police teams are carrying out raids to arrest the remaining accused. Additional forces have been deployed in the area to prevent fallout.
ADCP (East) Abhijit R. Shankar said that four youths – Samar, Abhilash, Dheeraj and Aman – were standing with their friends when Karan and his friends passed by. They hurled abuses at the four friends which led to a scuffle.
Supporters of both the groups started collecting and soon, they started pelting stones at each other.
The group led by Karan opened fire and three persons were injured. The shots were fired from a country made weapon.
The ADCP said that enmity between the two groups began almost three years ago over their supremacy in the area.
The official said that a case has been registered and the accused would be arrested soon.