The Syrian Observatory for Human Rights says two explosions near Shi'ite shrines in Damascus have killed at least 59 people and wounded more than 100.
There were conflicting reports about the cause of the explosions near Damascus's Bab al-Saghir cemetery, a site where Shi'ite mausoleums draw pilgrims from around the world.
Syria's SANA state news agency reported that "two bombs planted by terrorists exploded."
But Lebanon's Al-Mayadeen TV said one roadside bomb was detonated as a bus was passing and a suicide bomber blew himself up near another bus.
Local security sources told the German news agency dpa that the blasts targeted buses carrying Iranian visitors to a Shi'ite Muslim shrine.
But Iraq's Foreign Ministry said at least 40 Iraqi Shi'a were killed and 120 wounded.
There was no immediate claim of responsibility for the attack.
Based on reporting by Reuters, AP, AFP, and dpa