Syria's largest rebel group, Ahrar al-Sham, lost almost its entire senior leadership late on Tuesday, in an as-yet-unexplained explosion that took place during a secret meeting in Syria's northern Idlib governorate near the border with Turkey. While some reports have claimed a suicide bomber, a chemical attack, or a car bomb was responsible, the most likely scenario appears to be that a government airstrike targeted the meeting, which was taking place in an underground bunker. The airstrike set fire to an attached ammunitions depot, which consequently meant the bunker was filled with acrid smoke, causing suffocation. An apparent lack of bodily wounds on the victims' bodies would appear to fit this account.