Syria's defense minister, the brother-in-law of President Bashar al-Assad and another top Assad aide were all killed in a suicide attack on a meeting of top security and defense officials in Damascus on Wednesday, Syrian state media reported. The rebel Free Syrian Army claimed responsibility for the attack that killed Defense Minister Daoud Rajha, Assad's brother-in-law and deputy armed forces chief-of-staff Assef Shawkat and assistant vice-president Hassan Turkmani — but so did an Islamist rebel group, Al Jazeera reported. Others were reported seriously injured in the blast. The bombing came as rebel forces advanced on Syria's capital, clashing with regime forces in the fiercest fighting there since the conflict erupted last year. The U.N. Secretary General condemned the attack and pointed out that "violence committed by any party are unacceptable and a clear violation of the six-point plan" for peace, a statement from the U.N. said.