Twin bombs targeting Shiite pilgrims killed 59 people, mostly Iraqis visiting a shrine, in Damascus on Saturday, a monitoring group said.
The attack is one the bloodiest in the Syrian capital.
The twin blasts Saturday hit outside Bab al-Saghir cemetery, one of the most ancient in the Syrian capital and which houses revered Shiite religious figures.
Reports said that among those killed were 47 pilgrims and 12 Syrian pro-government fighters.
Levant Swords rebel group has reportedly claimed the responsibility of the double bombing attack on buses of Shia pilgrims parked outside the cemetery.
Ahmed Jamal, Iraq's foreign ministry spokesman, says in a statement initial reports suggest 40 killed were Iraqis. He said a crisis cell was formed in coordination with Syrian authorities to determine the identities of those killed and wounded and to transfer them to Iraq. The statement condemned the attacks.
Syrian Interior Minister Mohammad Shaar said the attack targeted "pilgrims of various Arab nationalities" adding that "the sole aim was to kill."
There have been periodic attacks in Damascus during the six years of civil war in Syria, but the stronghold of President Bashar al-Assad has largely been spared the destruction faced by other major cities.
Levant Swords group is allied with the rebels' Free Syrian Army (FSA), which is operating in areas in the southern countryside of Damascus, Xinhua cited Mayadeen TV as saying.
Meanwhile, the pro-government al-Watan online newspaper said that the bomb squads succeeded to defuse bombs mounted on a motorcycle that was supposed to go off in that area as well.