Two "terrorist" explosions hit near the army's Chief of Staff headquarters in the center of the Syrian capital, the state TV said, giving no further details on causalities.

The blasts were followed by intense gunfire, witnesses said, adding that a fire was still smoldering from the army building and sending a plume of smoke over the Umayyad Square.

Earlier, activists told the pan-Arab al-Jazeera TV said the blasts were carried by the rebel Free Syrian Army.

A major blast targeting the National Security Department in July killed four top military officials, including then Defense Minister Dawood Rajha.