An explosion inside the Syrian national security headquarters in Damascus targeted ministers from President Bashar Assad's regime who were meeting with defense officials on Wednesday, reportedly leaving some senior officials dead and wounded.


Citing Syrian TV, CBS News reports that Syrian Defense Minister Gen. Dawoud Rajiha was killed in the explosion. His death could not be independently confirmed, but State TV is a mouthpiece for the Assad regime.


State TV reported that other ministers and military officials were seriously injured in the explosion.


There were reports that Assad's own brother-in-law and deputy chief of staff Assef Shawkat was also killed in the blast. That could not be immediately confirmed, and Syrian State TV denied another report that Interior Minister Mohammed al-Shaar was dead, saying he was hospitalized in stable condition.


Opposition leader Kamal al-Labwani told al-Arabiya, a pan-Arab satellite channel, that a member of the rebel Free Syrian Army planted a TNT and C-4-based device inside the building ahead of the meeting, and then detonated the bomb remotely before fleeing to safety. There were conflicting claims, however, from other opposition figures, some of them claiming a suicide belt had been used in the attack.


The national security headquarters is said to be among the most tightly secured buildings in Damascus, suggesting the individual who planted the device likely was an insider. Officials have told Al Jazeera that the person who planted the device was one of the cabinet member's personal bodyguards.


The armed uprising against Assad's regime has intensified rapidly in recent weeks, with mounting military and political defections eroding his family's long-time grip on power as rebel forces engage his troops more frequently in Damascus, the president's seat of power.