Al-Qaeda's general command has disavowed all links with the Islamic State in Iraq and Greater Syria (ISIS), according to a statement posted online.
The statement, published late Sunday, reiterated a previous peremptory statement in which the group's chief Ayman al-Zawahiri ordered ISIS to disband and return to Iraq, and adding that the Nusra Front is Al-Qaeda's official branch in Syria.
"Al-Qaeda announces it is not linked to the Islamic State of Iraq and Greater Syria as it was not informed of its creation [and] did not accept it," read Sunday's statement, which also criticised ISIS's mode of operations.
ISIS, it said, "is not a branch of al-Qaeda, has no links to it, and the Al-Qaeda is not responsible for its acts."
"We affirm our disavowal from the sedition that is occurring in Syria between factions of jihadists, and from the blood that was shed by any party," it said.
In recent weeks, ISIS has consolidated its grip on the northern city of Raqqa, the only provincial capital to fall out of regime control since the outbreak of Syria's uprising in March 2011, and imposed their strict version of Shariah law on residents there.
ISIS also issued four statements ordering women to wear the niqab in public, forbidding the sale of cigarettes and narghile (water pipe) products, banning music and making attendance of Friday prayers compulsory.
It also killed the leaders of two rival rebel groups on Saturday.
Small but powerful, ISIS has been caught up in battles with other armed groups often triggered by disputes over authority and territory, and has also clashed with secular rebels.
The internecine fighting – among the bloodiest in the three-year conflict – has undermined the uprising against President Bashar Assad and dismayed Western powers pushing for peace talks.
Rebel-on-rebel violence in Syria has killed at least 1,800 this year alone. The tensions erupted in early January into armed clashes between ISIS and other rebel groups.
Charles Lister, visiting fellow at Brookings Doha Center, said the Al-Qaeda statement "represents an attempt to re-assert some level of authority over the jihad in Syria" following a month of fighting and ISIS disobedience.
"This represents a strong and forthright move by Al Qaeda and will undoubtedly serve to further consolidate the Nusra Front's role as Al-Qaeda's official presence in Syria."
Translated and edited by The Syrian Observer