A senior police officer told PTI, one person has been detained while a search was on for the main accused for the clash between the groups at the Collins Lane and Free School Street crossing.
Today's clash at around 8:30 pm is the sequel of a tiff between the same groups last night, he said.
Today one group allegedly led by Guddu and Lula Saanu attacked another with revolver as two rounds of firing took place, the police official said.
The injured, who was taken to the Chittaranjan Hospital, was released after check-up, he said.
Two days back a clash took place in Entally area of the city with shots fired and bombs hurled.