Four leaders of the Islamic State were killed by U.S. and Iraqi security forces in a combined raid carried out in western Iraq last month, including the head of the extremist group’s operations in the country, U.S. military officials announced Friday.

       The dramatic operation Aug. 29 resulted in the deaths of 14 Islamic State operatives and was designed to “disrupt and degrade” the terrorist group’s ability to organize and launch attacks throughout the region and beyond, U.S. Central Command said at the time.