The Islamic State group has said it was behind a string of suicide bombings near a Shiite shrine outside Syria's capital and in Homs that killed more than 150 people on

Sunday, as Washington and Moscow worked to secure a cease-fire.

The bombings occurred as US Secretary of State John Kerry said a provisional deal had been reached on the terms of a truce in Syria's brutal conflict.

Near Damascus, a car bombing followed by two suicide attacks ripped through the area of the Shiite shrine of Sayyida Zeinab and killed 96 people, according to the Syrian Observatory for Human Rights.

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