Among the victims of Saturday's blasts were 43 Iraqi pilgrims who had come to the Syrian capital to visit Shiite shrines in Damascus's famed Old City, according to the Syrian Observatory for Human Rights.
The Britain-based monitor said that 11 bystanders and eight children were among those killed, as well as 20 members of pro-government security forces.
Observatory head Rami Abdel Rahman told AFP that a roadside bomb detonated as a bus carrying pilgrims made its way through the Bab al-Saghir area of the Old City before a suicide bomber blew himself up.
Syrian state television on Saturday gave a toll of 40 killed and 120 wounded by "two bombs detonated by terrorists".
Signup to our newsletter and follow us on Facebook and Twitter!
Iraq's foreign ministry said around 40 of its nationals had died.
No group has so far claimed responsibility for the attack.
Shiite shrines are a frequent target for Sunni extremists of Al-Qaeda and the Islamic State group (IS), not only in Syria but also in neighbouring Iraq.
The Sayyida Zeinab mausoleum to the south of Damascus, Syria's most visited Shiite pilgrimage site, has been hit by several deadly bombings during the war.
Twin suicide bombings in the high-security Kafr Sousa district of the capital in January killed 10 people, eight of them soldiers.
That attack was claimed by former Al-Qaeda affiliate Fateh al-Sham Front.