Bomb blasts killed more than 100 people in the Syrian coastal cities of Jableh and Tartous on Monday, May 23, monitors said, in a government-controlled area that host Russian forces, Reuters says.
Islamic State claimed responsibility for the attacks in the Mediterranean cites that have up to now escaped the worst of the conflict, saying it was targeting supporters of President Bashar al-Assad.
Scores were wounded in at least five suicide attacks and two car bombs, the Syrian Observatory for Human Rights said, the first assaults of their kind in Tartous, where government ally Russia maintains a naval facility, and Jableh.
State media confirmed the attacks but gave a lower toll, Reuters says.
Footage broadcast by the state-run Ikhbariya news channel of what it said were scenes of the blasts in Jableh showed several twisted and incinerated cars and minivans.
Pictures circulated by pro-Damascus social media users showed dead bodies in the back of pick-up vans and charred body parts on the ground, Reuters says.
The Syrian Observatory said at least 53 people were killed in Jableh, and 48 in Tartous.
The interior ministry said in a statement more than 20 people had been killed, and one state media outlet put the death toll at 45 people.