The Dallas Police Department has set up a series of sting operations to catch out Mexican immigrants selling frozen fruit treats from pushcarts.

The immigrants, palesteros, are buying up the popular products, paletas, in bulk from distributors who own the carts and obtain the licences. They then sell the items at about a 50% mark-up.

According to a report in the Wall Street Journal Europe, tensions are mounting around the illegal traders and the workers of city-licensed concession stands, and turf wars are common as the market is flooded.

The paper highlights the case of 48-year-old Fernando Garduza, who immigrated to Texas five years ago. He does not have US working papers and started working as a bricklayer, but earned only US$100 a week. With the help of false identification however he now sells paletas and brings in several hundred dollars in wages a week, enough to send some money back to his wife and children in Mexico.