Most of the dead in Saturday's attack were Iraqi Shi'ites who were going to visit a cemetery near the Old City of Damascus.
According to Reuters, there has been no claim of responsibility. The Hezbollah-run al-Manar TV station said it was carried out by two suicide bombers.
Syrian President Bashar al-Assad has been supported in the country's war by Shi'ite militias from countries including Iraq, Afghanistan and Lebanon.