July 18 (UPI) -- The fight against terrorism extended into the oil industry as the Western-led coalition said it hit storage tanks in Syria controlled by the Islamic State.
The U.S. Defense Department said forces united under Operation Inherent Resolve struck oil installations in the 25 strikes carried out recently against fighters with the Islamic State in Syria.
"Near Abu Kamal, two strikes destroyed four ISIS oil refinement stills, three oil storage tanks and three oil barrels," the Pentagon said in a strike update. "Near Dayr Az Zawr, six strikes destroyed 12 ISIS oil refinement stills, four wellheads and two oil storage tanks."
Three years ago, consultant firm IHS estimated the oil production controlled by the terrorist group was worth $800 million per year, based on the 2014 market. Oil at the time was fueling the war chest for regional terrorism with more than $2 million per day
Oil fuels the terrorist group's operation by powering military vehicles and financing its activities through revenue on the black market.
By 2015, the U.S. Defense Department said the terrorist group was no longer relying on oil as its main source of revenue to fund its operations. But in March, a U.S. defense official speaking on condition of anonymity to Stars and Stripes, the military's editorially independent news agency, said the Islamic State has lost its grip on oil in Iraq, but still maintains control in some parts of Syria.
"Their largest cash revenue is still an ability to extract oil and gas and to refine and sell it," the official said.
The terrorist group during the weekend set several oil wells on fire in southern Syria, after national forces recaptured them just days before.
The Islamic State once supplied oil to foreign customers in the regional black market, but has focused more of its supply to fuel its own operations. A report from the Brookings Institution said this is why coalition forces target oil installations more than oil supply routes.