Syrian rebels backed by US launch attack on ISIL at Raqqa

Reuters:

U.S.-backed rebels said on Sunday they were launching an operation to retake the Syrian city of Raqqa, the de facto capital of Islamic State.

The attack ratchets up pressure on the militant group at a critical moment, with its fighters already battling an offensive by Iraqi security forces on their remaining Iraqi stronghold in the northern city of Mosul.

The U.S.-backed Syria Democratic Forces (SDF), an alliance of Kurdish and Arab armed groups, first announced on Sunday that a campaign to retake Raqqa would begin within hours, with U.S. forces providing air cover. Soon afterwards, it said that the operation, called Euphrates Anger, had begun.

"The general command of the Syria Democratic Forces announces the blessed start of its major military campaign to liberate the city of Raqqa," Jehan Sheikh Amad, an SDF spokeswoman, told a news conference in the Syrian town of Ain Issa.

The SDF called on Raqqa's civilians to avoid areas where Islamic State militants are present and to go to "liberated territory".
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This should create a dilemma for ISIL forces retreating from Mosul.  It will be hard for them to find a "safe space."