The U.S.-led coalition in Syria said on Tuesday it had disrupted Islamic State's funding by killing the man who ran its oil and gas network and other members of the group last month.
"The death of these (Islamic State) members hinders the terrorist group's ability to finance operations throughout Iraq and Syria ... the ability to pay fighters, procure weapons, and maintain equipment will be degraded," it said in a statement.
The coalition said it killed the oil and gas network leader Abu Khattab al-Iraqi and three other Islamic State members on May 26 in the "Middle Euphrates River valley".
Al-Iraqi had "managed revenue generation through the illicit sale of oil and gas", it said.
In Syria the U.S.-led coalition uses air power and special forces to back the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias, in their fight against Islamic State.
The SDF took swathes of northern and eastern Syria from Islamic State last year, including the jihadists' Syrian capital of Raqqa. It continues to fight Islamic State in some desert areas east of the Euphrates.