Islamic State claimed responsibility for the attacks in both cites that have up to now escaped the worst of the conflict, saying it was targeting members of President Bashar al-Assad's Alawite minority.
 
The British-based Syrian Observatory for Human Rights said more than 120 people were killed. State media claimed 78 people died.
 
Attackers set off at least five suicide bombs and two devices planted in cars, the first assaults of their kind in Tartous, where government ally Russia maintains a naval facility, and Jableh in Latakia province, near a Russian-operated air base.
 
Syria's Information Minister Omran al-Zoubi said in an interview with Ikhbariya that terrorists were resorting to bomb attacks against civilians instead of fighting on the frontlines, and vowed to keep battling them. Take note that Damascus refers to everyone opposing the regime as terrorists as well.
 
Fighting has increased in other parts of Syria in recent weeks as world powers struggle to revive a threadbare ceasefire and resurrect peace talks that collapsed in Geneva this year.
 
Government forces and their allies have recently stepped up bombardment of areas in Aleppo province in the north, which has become a focal point for the escalating violence. Insurgents have also launched heavy attacks in that area.