A Syrian opposition source says there are doubts in the country that a bomb attack killed four senior Syrian officials Wednesday.
Media reports from the region initially called the explosion that killed Assad's defense minister and brother-in-law the work of a suicide bomber. Later reports claimed a bodyguard wearing a suicide vest was responsible. But after Syrian state media outlets ceased referring to the strike as a suicide bombing, it suddenly became unclear just what killed the senior officials.
A BBC reporter in Damascus injected further questions into the situation Wednesday when she tweeted this: "Just walked around national security building and saw no sign of explosions, no broken window, no heavy security presence."
"The facility that was allegedly attacked is one of most secure buildings in Damascus, so I cannot imagine that explosives were planted secretly," the opposition source says. "I have talked with the actual [Free Syrian Army] leadership and there is no clear indication what happened.
"Some people living close by the facility say they didn't hear any explosion," the opposition source says. "For the state media to come out so quickly and announce something like that is unusual and unheard of in Syria. Usually, they deny things like this; here, they come out and announce it."
One explanation for why the Assad regime would fashion such a story would be to hide multiple previous rebel attacks that succeeded in methodically degrading Assad's inner circle, which sources and experts say is crucial to his survival as president.
CIA and Office of the Director of National Intelligence officials were unable Thursday to shed new light on just what kind of device was used. Suicide bombings are a favorite tactic of terrorist groups like al Qaeda, and using one could hurt the opposition's efforts to rally support inside Syria and across the globe.
At the United Nations, Russia and China vetoed a Security Council resolution that would have invoked Chapter Seven of the U.N. charter. That would have allowed the 15-member council to approve a range of future actions, both diplomatic and military.
Meantime, confusion about Assad's health and whereabouts also were rampant 24 hours after the blast that targeted his top national security aides. Several reports from Syria said the longtime strongman had been injured or killed in the attack; others reported he had fled the capital city; and Syrian state television aired footage of the president on Thursday.
Officials inside the Syrian intelligence community have told rebel officials it is unclear just where Assad is, the opposition source says.
Many Middle East experts believe the attack on the national security facility is the beginning of the end of Assad's tenure because it reveals members of his military and inner circle have turned on him.
Marina Ottaway of the Carnegie Endowment for International Peace, says the strike has all the hallmarks of an inside job. Many experts and Syrian opposition figures already are thinking a post-Assad Syria.
One opposition source predicts Assad will be ousted from the presidency within weeks.
Ottoway says while some expect chaos to grip Syria as various individuals and factions jockey for power, "there are indications that the opposition is getting better organized."
"I don't think it will be a free-for-all," Ottaway says. "But we are likely to see conflict between those people who are representing Syria outside of the country and the Free Syrian Army--the people who are fighting inside the country." The Syrian opposition source says the resolution's failure is unlikely to affect the ongoing civil war, which has killed over 17,000 people.
"The international community has done a lot of talking, but not a lot in the way of supporting the opposition. The international community has contributed just $50 million--that should be embarrassing for the West," the opposition source says, noting rebel proponents inside the country have donated $100 million more.
"We're taking matters into our hands," the source adds. "We'll finish what we started."
John T. Bennett covers national security and foreign policy for U.S. News & World Report. You can contact him at firstname.lastname@example.org or follow him on Twitter.