Police in India’s commercial capital Mumbai have arrested three gangsters after they duped a snack shop owner and his friend of about $7690, promising them US dollars at a cheaper exchange rate.

Promptly acting on a complaint filed by the snack shop owner Itesham Hyder and his tailor friend Irshad, Mumbai Police arrested Mustafa Vyapari, Sohail Khan and Bhanu Shaikh in various locations in the city, The Times of India reported.

Police said the accused approached the victims and told them that the desperate Bhanu Shaikh wanted to convert dollars into rupees and was willing to do so at a lower exchange rate. They then handed over a bundle of papers with two US dollars on top, wrapped in a handkerchief, to the victims Hyder and Irshad.

The gangsters used a mobile app to snare their victims, and it took police over a week to apprehend them. The fraudsters were running a similar racket in India’s capital, New Delhi; the report quoted a police officer as saying.

Police recovered a portion of the stolen money, which was in possession of the accused when they were picked up. Authorities are now looking for the mastermind behind the crime.