Riad Al-Asaad, a Turkey-based air force colonel who heads the Free Syrian Army, says in a video posted online that the attack was “fabricated” by President Bashar Assad’s regime to harm the image of the “revolution.”

Al-Asaad’s statement late Sunday came hours after his group claimed responsibility for the attack in a statement posted on its Facebook page. It was not clear why the FSA retracted its claim.

Al-Asaad said his group does not attack civilian targets.

Activists said rocket-propelled grenades struck the Baath party headquarters early Sunday.