After a month of U.S. led airstrikes the extremist group Islamic State is facing a major downturn in oil production used by the group to fund its activities.
The Paris-based International Energy Agency reported that total oil production from fields captured by Islamic State has dropped from about 70,000 barrels per day to 20,000 barrels per day.
Before the airstrike campaign Islamic State controlled seven oil fields and a refinery in northern Iraq as well as six oil fields in eastern Syria.
In September, the airstrikes destroyed 15 Syrian refineries captured by Islamic State.
According to the report, the air campaign in northern Iraq and Syria is “frustrating the jihadists’ ability to operate oil fields and refineries.”
The IEA said that at peak output Islamic State was sending about 120 tanker trucks carrying about 20,000 barrels of oil per day from Iraq and through Kurdistan.
The airstrikes have slashed shipments to about 10 trucks per day, or about 2,000 barrels of oil per day.
The U.S. led campaign has also taken out “dozens of teapot refineries” in Syria the IEA said, squeezing Islamic State’s gasoline supply.
Kurdistan and Turkey are also ramping up their efforts to curtail smuggling, seizing tanker trucks controlled by Islamic State and arresting the drivers.
Production from the captured assets was bringing in an estimated $2 million a day for the Sunni extremist group that was used to fund its military operations.
Islamic State sells the oil products processed at its refineries on the black market and to smugglers who then sell the product on the gray market in Turkey, Iran and Jordan.
Some of the oil is also sold to the Syrian government.
Most of the transactions are paid for in cash, making it difficult to track the deals or stop them, Bloomberg said.