WASHINGTON (Sputnik) — Kadek, also known as Rayan Mashaal, was killed on Monday in the town of Mayadeen near the Syria-Iraq border.
"Mashaal and his daughter were killed in a coalition airstrike on Mayadeen," the group Eye on the Homeland wrote.
Syrian activist groups did not detail how Kadek was killed and the coalition has not confirmed his death.
Daesh's news agency publishes official information from the terror group, often including the group's first claims of responsibility for terrorist attacks. It is widely seen as a terrorist propaganda outlet.
Kadek, a former Syrian opposition activist, reportedly created Amaq after joining Daesh in 2013.