Bomb blasts kill scores of people in Jableh and Tartous on Syria's Mediterranean coast with many others wounded in the government-controlled territory that hosts Russian military bases, monitors and state media said.

Syrian rebels seize control of the Islamic State group's main supply route to Turkey, a monitor says.

At least 45 civilians are killed Sunday in heavy bombardment of a besieged Syrian rebel stronghold east of Damascus that also struck a school, a monitoring group said.

Syrian government war planes have launched one of the heaviest bombardments yet on the city of Palmyra, which is held by Islamic State (IS) militants, activists say.

The Islamic State group beheads two women in Syria on accusations of "sorcery," the first such executions of female civilians in Syria, the Syrian Observatory for Human Rights.

At least 16 people, including 13 children, are killed when Syrian air force jets bombed a town in Deraa province on Tuesday, activists say.

Nineteen of 220 members of an Assyrian Christian community kidnapped by Islamic State (IS) in Syria released