Twin blasts hit near the headquarters of the army general staff in the heart of Damascus early on Wednesday, state television said, without giving any immediate word on any casualties.
The early morning explosions sparked a fire in the Syrian capital's closely guarded Umayyad Square
administrative district, the television said.
The Syrian Observatory for Human Rights said that one of the blasts hit right in the heart of the district and the second in Kfar Susa neighbourhood slightly to the west.
The Britain-based watchdog said that both blasts were accompanied by automatic weapons fire.