Al Qaeda's general command said on Monday it had no links with the Islamic State in Iraq and the Levant (ISIL), in an apparent attempt to reassert its authority over fragmented Islamist fighters in Syria's civil war, Reuters reported.
After a month of rebel infighting, al Qaeda disavowed the increasingly independent ISIL in a move likely to bolster a rival Islamist group, the Nusra Front, as al Qaeda's official proxy in Syria.
The switch is seen as an attempt to redirect the Islamist effort towards unseating President Bashar al-Assad rather than waste resources in fighting other rebels, and could be intended to shift the strategic balance at a time when government forces are increasingly active on the battlefield. It could also embolden Nusra in its dispute with ISIL.
Overall, the three-year-old war however remains largely deadlocked, with Syria fragmented into areas controlled by the warring parties.
ISIL has fought battles with other Islamist insurgents and secular rebel groups, often triggered by disputes over authority and territory. Several secular and Islamist groups announced a campaign last month against ISIL.
The internecine fighting - some of the bloodiest in the war so far - has undermined the uprising against Assad and dismayed Western powers pushing for peace talks between the government and opposition.
Rebel-on-rebel violence in Syria has killed at least 2,300 this year alone, according to the Syrian Observatory for Human Rights monitoring group.
ISIL follows al Qaeda's hard-line ideology and, until now, the two groups were officially linked. Many foreign fighters and ISIL observers, however, say that al Qaeda central and ISIL had in fact been effectively separated since before the group, which was originally the al Qaeda branch in Iraq, spread into Syria.
Hard-line Islamist rebels, including Nusra, have come to dominate the largely Sunni Muslim insurgency against Assad, who is supported by his minority Alawite sect - an offshoot of Shi'ite Islam - as well as Shi'ite fighters from Iraq and Lebanon's Hezbollah.
In a message on jihadi websites on Monday, the al Qaeda General Command said ISIL "is not a branch of the al Qaeda group.
"...(Al Qaeda) does not have an organizational relationship with it and is not the group responsible for their actions."
In April, ISIL head Abu Bakr al-Baghdadi tried to force a merger with the Nusra Front, defying orders from al Qaeda chief Ayman Zawahri and causing a rift.
A Nusra commander in northern Syria told Reuters that the statement meant that his group's position was no longer one of neutrality.
"Now we are going to war with ISIL and will finish it off once and for all," he said on condition of anonymity.