Deadliest bomb blasts in Syaria left atleast 120 killed and 180 others injured, media reported on Sunday.
In Homs, twin car bombs killed at least 57 people and wounded 100, and explosions hit parts of the capital, Damascus, killing a further 62 and wounding 180, according to the UK-based Syrian Observatory for Human Rights.
The attacks on both cities were claimed by Islamic State.
Both attacks targeted areas dominated by minorities within Islam reviled by the Sunni Muslim radicals of IS.
In Homs, the blasts happened in a predominantly Alawite district, the sect to which President Bashar al-Assad belongs.
In Damascus, at least four explosions were reported in Sayyida Zeinab, the location of Syria’s holiest Shia Muslim shrine, said to contain the grave of the Prophet Muhammad’s granddaughter.
State television reported at least 50 dead and 200 wounded. Other reports put the death toll higher.
Meanwhile the US secretary of state John Kerry told media on Sunday that a “provisional agreement” on a ceasefire in Syria has been reached between the US and Russia, but serious doubts remain on whether it will come into force as the country reeled from a series of deadly car bombs in Syria’s two biggest cities.
Kerry said he had reached an agreement following phone talks with his Russian counterpart Sergei Lavrov, amid signs that Russia is putting some pressure on Syrian president Bashar al-Assad to comply. There are serious doubts over strength of the deal, which would need the agreement of Vladimir Putin and Barack Obama, who are expected to speak by phone later this week.
A previous UN-brokered ceasefire, agreed between the interested parties in Munich a fortnight ago, failed to come into force on Friday as expected, with Russia continuing its bombing campaign and the Syrian army moving to encircle Syria’s second city of Homs.