Militants from the Islamic State of Iraq and Syria (ISIS) expand control and continuously earn an estimated $1 million to $2 million daily through oil smuggling, donations, and through domestic criminal activities, according to CNN report.

Small villages in the Syrian border depict serene sceneries, far from the chaotic Northern Syria where the ISIS is fighting a stern battle in its attempt to confine and control new territories. The aim of the Islamic group to conquer Islamic caliphate originates from the first caliphate that started around 640 A.D. after Prophet Mohammad's death. Recently, smuggling of multi-million oil barrels by the Islamic state group was discovered as they expand their control in the border region including the town of Besaslan.

After controlling territories, the ISIS fighters made an easy way to seize number of oil fields in the Northern Iraq and Northern Syria. This time smuggling becomes easier even in the Southern part of Turkey. Since oil is highly expensive in Turkey, the group has successfully sold oil barrels at a much cheaper price. Gasoline in Hatay, Turkey alone costs $7.50 per gallon, while it is believed that the group offers the smuggled oil at its discounted rate of $25 to $60 per barrel. The oil being sold by the ISIS amounts to less than half of its international cost, analyst states.

Theodore Karasik, Director of Research and Consultancy at the Institute for Near East and Gulf Military Analysis told ABC News that the revenues generated from the oil smuggling support a big portion of the group's financial funding.

Sources declared that for oil revenues, the group is earning between $1 million to $2 million daily. This is rooted for the huge expenses that ISIS is funding including weapons, salaries and other expenses.

"The best-financed group we've ever seen," Matthew Levitt, Director of the Stein Program on Counterterrorism and Intelligence stated at the Washington Institute for Near East Policy in Washington stated. He added the group also generates funds from rich sympathizers in Kuwait and Qatar, and from organized crime activities within the areas it controls. Moaz al-Khatib, a former president of the National Coalition for Syrian Revolutionary and Opposition Forces stated that Iraq antiques are also being sold by the group in Turkey where the group is said to be generating millions of dollars,

Last week, U.S. led coalitions forces attacked ISIS oil facilities to stop ISIS funding.