Katz added Amaq had "shown itself as ISIS' state media agency" since its founding in 2014 and had issued claims for at least two dozen attacks around the world. Islamic State militants control swathes of Syria's vast eastern deserts and most of Deir al-Zor province bordering Iraq, but they have been on the back foot over the past year. With air strikes and special forces on the ground, the US-led coalition is supporting an alliance of Kurdish and Arab militias in a campaign to capture Raqqa city. The Syrian Democratic Forces are advancing on Raqqa, Islamic State's urban base of operations in Syria, and have seized tracts of territory in northern Syria from the jihadist group. The SDF, which includes the powerful Kurdish YPG militia, expect to storm Raqqa in early summer with the help of new weapons from the coalition. Islamic State is losing ground in both Syria and Iraq under assault from an array of sometimes rival forces in both countries. Many of its fighters who have retreated from other fronts are believed to be massing in Deir al-Zor. The Syrian Observatory for Human Rights said air strikes in al-Mayadin last week killed more than 100 people including children and other family members of Islamic State fighters. The Britain-based war monitor said coalition warplanes killed more than 40 children and leveled the municipality building. The U.S.-led coalition says it is careful to avoid civilian casualties in its bombing runs in Syria and Iraq, and investigates any allegations.1) Breaking: A founder of #ISIS' Amaq allegedly killed by coalition airstrike in DeirZour. Identified as "Barra'a Kadek" AKA"Rayyan Mesha'al pic.twitter.com/XHUSNr6BMe
— Rita Katz (@Rita_Katz) May 31, 2017