Need an advice to remove unauthorised fish sales in a narrow residential street

Dear Sir/Madam, Kindly advice how to deal with the below problem. I and my family live in a corner row house in a residential area of Chennai with 2 tenants. There is a demolished house on the 8 feet side street facing our house. From last month a couple from our next street started SELLING, STORING, CUTTING and CLEANING the fish in front of the demolished house (though they are not the owners of that demolished house). The stored fishes, waste water, selling of fish and left over fish waste give bad smell inside my house like a fish market. Lots of mosquitoes and flies buzz there and spread to my house as well as we have our windows and ventilation on that side only. The whole place has become messy and smelly. We are not able to bear with the bad odour and fish sales is causing health and hygiene issues inside our house. Please suggest some legal remedies to remove this unauthorised fish shop opened without permission from any authorities. Thanking you in advance. Sincere Regards, Mani