Fighting between rebel factions in Syria is complicating an already complex civil war.

While still a broad regional confrontation between Sunni and Shi’ite Muslims – battles between different Islamist factions and non-Islamist rebels are weakening the stance against Syrian government troops.

On Sunday fighters loyal to al-Qaeda pulled back from ground near the Turkish border giving way to rival Islamists after sustaining heavy losses in the last few days.

Resentment is growing over the intervention of the al-Qaeda loyalists who have foreign jihadists among their leaders and want to build their own Islamic state in Syria..

Meanwhile there are divisions on the political front.

Ahmad al-Jarba was re-elected at a congress in Istanbul as leader of the the Western-backed Syrian opposition, but there are other disputes to be resolved.

A vote is due on Monday to decide whether to take part in talks with delegates representing President Assad at the Geneva 2 gathering.