A bomb ripped apart the highest echelons of Syria's security establishment Wednesday.
The blast went off during a top-level meeting at the National Security building in the capital, Damascus.
Syria's state TV says the blast killed the defense minister, Daoud Rajiha, and his deputy Assef Shawkat, who was President Assad's brother-in-law.
Syria's intelligence chief and the nation's Interior Minister were reportedly wounded.
The BBC's Lina Sinjab is in Damascus and after the bombing, she went on a government-run press tour of the city. The tour ended at Seven Fountains Square, where Sinjab says the atmosphere was eerie. She talks to anchor Marco Werman to give more details.
Werman also talks to the BBC's security correspondent, Frank Gardner, who says there are many conflicting rumors and conspiracy theories about what happened.
"But if indeed it is a suicide bombing, carried out — as has been suggested — by one of the bodyguards of the people at this top-level national security meeting, then it's a triple blow for Bashar's regime," Gardner said.
According to Frank Gardner, firstly, it's a personal blow to his family. Second, it damages the regime's command and control structure. Thirdly, it's a blow that someone could penetrate to the heart of the regime and do this. It could cause many to look over their shoulders and ask if it's time to jump ship.