Governor Talal al-Barazi told AFP the car bomb detonated in the Zahra neighbourhood in the central city, killing 36 people, adding that the blast was followed by a rocket that killed nine others.
Most of the neighbourhood’s residents are from the Alawite community, like Syria’s President Bashar al-Assad..
The Syrian Observatory for Human Rights, a monitoring group based in Britain, said the toll was at least 37 dead and nearly 80 injured.
Observatory director said all of the dead were civilians, among them at least five children.
Barazi said the high death toll was because “the Abbasiya area where the bomb detonated was crowded with pedestrians”.
“The rocket fell about half an hour after the bombing on the same area, where there was a crowd of people” trying to help those injured in the blast, he said.
The attack was one of the deadliest to hit the central city, where rebels control just a few remaining districts, most of them under a tight government siege.
In the Old City, under siege for nearly two years, a few hundred fighters remain after a UN-led operation to evacuate civilians left to survive with almost no food or medicine.
Earlier this month, the Syrian army launched a ground assault against rebel-held parts of the city, entering some neighbourhoods for the first time in nearly a year.