More than 150 people in total are said to have been killed in bomb attacks in the Syrian cities of Damascus and Homs.
In the capital, 180 were also wounded when four explosions hit the southern Sayeda Zeinab district.
“I was sleeping at home upstairs when I heard the first blast. It happened right here. About five minutes later, when I was calling the ambulance here, the second bomb went off,” said one witness in Damascus.
In Homs, dozens were killed in twin car bomb explosions. ISIL says it was behind the attacks in both cities.
Suffering and destruction in Syria has worsened further since Russia launched air strikes.
US Secretary of State John Kerry said on Sunday that a ceasefire in Syria was still possible. He added that he had reached a provisional agreement with his Russian counterpart.
“A cessation of hostilities, a hudna, is possible over the course of these next hours,” said Kerry.
Syrian President Bashar al Assad has stressed that he is ready for a ceasefire. On the condition, he says, that “terrorists” do not turn a lull in fighting to their advantage – and that countries backing insurgents pull the plug on their support.