The United States wants to hit the Islamic State (Isis) exactly where it hurts -- its revenue sources; and for this, it is ready to pay $5 million to anyone who can tell them how to stop Isis from making money through oil and antiquities.

The US Department of State on Tuesday (29 September) released a circular requesting general public for tips to "disrupt" Isis' oil and antiquities trade business, NBC news reported.

It is reportedly the first time that the US Secretary of State is offering a bounty on something like that. The US wants to destroy Isis' oil and antiquities business, but it does not know how.

 "Rewards for Justice program is offering a reward of up to $5 million for information leading to the significant disruption of the sale and/or trade of oil and antiquities by, for, on behalf of, or to benefit the terrorist group Islamic State of Iraq and the Levant (ISIL), also known by its Arabic acronym as DAESH."

In 2014, Forbes listed Isis as one of the richest terrorist organisations in the world with an annual income of $2 billion. It was then reported that Isis was making more than $1 million by selling crude oil alone.

Since then, the terror group has also started smuggling stolen antiquities. There also have been reports that the Sunni terror group is now into human organ trading as well.

With the announcement of the reward, the US Department of State hopes that it will be able to get information on "individuals or entities engaged in the production, facilitation, processing, smuggling, distribution, sale, and trade of oil and antiquities that benefit ISIL, as well as information regarding smuggling networks, methods, and routes underlying these activities."