Tensions between rival Syrian rebel groups boiled over Saturday near Ras al-Hosn, in the north of Idlib province.
According to the Syrian Observatory for Human rights, fighters from the Free Syrian Army (FSA) clashed with jihadists from the Islamic State of Iraq and Syria (ISIS), exposing a growing rift between Al Qaeda-affiliated groups and their Syrian rebel counterparts.
Saturday's clashes were only the most recent example of the escalating hostilities between the FSA - whose goals in the 2-year Syrian uprising are more localised and whose leadership is considered more "moderate" - and Al Qaeda-affiliated groups such as ISIS, whose ranks are made up largely of foreign fighters.
ISIS and other radical Islamist rebels, such as the Nusra Front, reject what they see as the "un-Islamic" notions of nationalism espoused by the FSA, in favour of the imposition of strict Islamic Law (sharia) in the region. They further view the Syrian conflict as merely one stage in a larger war against the "enemies of Islam", including Shia Iran, Israel and western powers. The FSA, though made up of a variety factions with differing views of how a future Syria should look, remains focussed purely on ousting the Assad regime and ending decades of domination by his minority Allawite faction and its allies.
These latest clashes apparently occurred after ISIS fighters attempted to seize weapons from a local FSA battalion, and came only days after the Al Qaeda franchise apparently assassinated an local FSA commander.
According to the Observatory, last week "dozens" of FSA fighters were killed in a battle against ISIS, after which the FSA battalion chief was beheaded.