A clash broke out at a railway siding near Ballygunge station on Saturday after a section of shanty dwellers resisted an eviction drive by the railways.
A team of Railway Protection Force officers had to backtrack after fierce opposition.
Several hundreds reside in settlements around the railway siding area with a majority involved in loading and unloading of goods from wagons.
Ekalabya Chakraborty, chief public relations officer of Eastern Railway, said concrete structures, including houses had come up on 47 of the total 111 plots earmarked for loading and unloading of goods.
Senior officers of Calcutta police said they had not received any intimation from the railway about drive.
Rajesh Shaw, a trader in the area, said: “We have valid papers that allow us to participate in loading and unloading of goods from wagons. How can they ask us to leave?”