Kurdish forces backed by US warplanes battled Saturday to retake Iraq's largest dam from Islamic State jihadist fighters, whose latest atrocity was a massacre in a Yazidi village. Two months of violence have brought Iraq to the brink of breakup, and world powers relieved by the exit of long-time premier Nuri al-Maliki were flying aid to the displaced and arms to the Kurds. Kurdish forces attacked the IS fighters who wrested the Mosul dam from them a week earlier, a general told AFP.