Jabhat al-Nusra, the much-feared militant jihadist group that has taken control of large rebel-held areas of northern Syria, has split in two following its leadership's public declaration of allegiance to al-Qa'ida.
Some of its fighters have withdrawn from the front line against the Assad regime in the northern Syrian city of Aleppo, rebel leaders told reporters, and appear to have turned their back on their Syrian leader.
Many Jabhat fighters had been recruited from other, rival militias with the promise of better-funded and better-organised units rather than for ideological reasons.
But they are said to have become disillusioned since their Syrian leader, Abu Mohammed al-Jolani, affirmed his loyalty to al-Qa'ida after an apparent takeover at the top of Jabhat by hardline jihadists from Iraq.
"The group has split," Mohammed Najib Bannan, the head of the Aleppo Judicial Committee's military arm, said.
The committee is backed by the major rebel brigades and runs civil and criminal courts in Aleppo alongside the city's Sharia court.
The West fears that the Syria conflict might come to replicate even more the murderous sectarian carnage of post-invasion Iraq. In much of north-east Syria up to the Iraqi border, Jabhat and another radical militia, Ahrar al-Sham, dominate the rebel movement and have arrested rival brigade leaders.
Last week they paraded three hooded men they said were Assad soldiers in the square before shooting them in the back of the head. The executioner said he represented the 'Islamic State of Iraq and Syria'.
Aymenn Jawad Al-Tamimi, a researcher on Arab politics, said recent videos claiming allegiance to the new organisation were largely from the east, while the Jabhat al-Nusra designation survives in those from the west.
"All this suggests Jabhat's name and symbols are beginning to be replaced by that of ISIS, and this trend has become particularly apparent in the east," he said. (© Daily Telegraph, London)