At least 59 people are dead and scores are wounded in a double bomb attack against buses full of Shiite pilgrims, mostly Iraqis, parked in front of a cemetery in downtown Damascus, the Syrian Observatory for Human Rights says.
The two explosions on Saturday occurred in the area of Bab al-Saghir Cemetery in the historic centre of Damascus, causing the death of 47 pilgrims and 12 members of security forces loyal to Syrian President Bashar al-Assad, according to the NGO.
The observatory said that one bomb exploded near the entrance to the cemetery on the parking-lot side, where nine buses were parked, and after that a suicide bomber on the cemetery grounds detonated the belt packed with explosives that he wore strapped to his body.
The second blast went off some 10 minutes after the first, inflicting casualties on civil defence workers who had gathered to tend to the victims, the Damascus correspondent for al-Manar told the station by phone.
The NGO said the number of fatalities might well increase because several of the wounded are in critical condition.
The Syrian government previously reported that "more than 40" were killed and close to 120 wounded in that attack, the worst committed in the Syrian capital in over a year.
Syrian President Bashar al-Assad has been supported in the country's war by Shi'ite militias from countries including Iraq, Afghanistan and Lebanon.
No terrorist group has as yet claimed responsibility for the attack, though the Syrian Foreign Ministry has accused in a statement both Islamic State jihadists and the old affiliate of al-Qaeda.
The Shiite pilgrims had travelled to Damascus to visit the sacred sites in that city, the Iraqi Foreign Ministry said.
The pilgrims were due to pray at the cemetery after visiting the Sayeda Zeinab shrine just outside Damascus, he said.
Sayeda Zeinab - the granddaughter of the Prophet Mohammad - is venerated by Shi'ites and her shrine is a site of mass pilgrimage for Shi'ites from across the world. It has also been a magnet for Shi'ite militiamen in Syria.