A rebel jihadist group has been pulling back from positions in North-Syria after being given an ultimatum by a rival, the BBC reportsThe Islamic State of Iraq and the Levant (Isis) is said to have been retreating towards the city of Raqqa.
The Nusra Front has given Isis until Saturday to accept mediation or face being expelled from Syria.
Infighting between rival rebel groups has seen more than 3,000 people killed in the past two months.
The main confrontation is between Isis and other Islamist militant groups.
|Abu Khaled al-Suri (AFP)|
He demanded that Isis halt all military operations against other rebels, and allow an Islamic court to rule on its actions.
The threat came after the killing of an al-Qaeda emissary, Abu Khaled al-Suri, in a suicide attack on in the northern city of Aleppo on Sunday. Rebel groups blamed ISIS for the bombing.
The latest reports suggest ISIS is taking the threat from the Nusra Front seriously, the BBC's Arab affairs editor Sebastian Usher says.