The self-styled Free Syrian Army said Monday that its fighters in the northern province of Aleppo killed the second-in-command of the al Qaeda-linked Islamic State in Iraq and the Levant.
"The combatants on the northern periphery of Aleppo (city)" reported having killed Haji Bakr in a clash, the FSA said on Twitter.
The FSA described Bakr as the top deputy of ISIL leader Abu Bakr al-Baghdadi.
The post included two photos of the dead man.
Hanein, a Web site used by jihadist factions, published on Monday an "elegy for the death of Haji Bakr, accepted by God," along with a photo of his remains.
A ragged coalition of the FSA and various Islamist factions - including al Qaeda affiliate al Nusra - have been fighting since New Year's to drive the ISIL out of northern Syria.
Though all parties to Syria's nearly 3-year-long civil war have committed atrocities, the ISIL has a reputation for being particularly savage and the other forces battling President Bashar Assad's regime see the group as a hindrance to their efforts.
Al Qaeda's leader, Ayman al Zawahiri, spoke out last Thursday to call for an end to internecine strife among the rebels in Syria.
"The struggle among the Islamic brothers who are confronting the regime of the ... murderer al-Assad (should) stop immediately," he said in an audio message.
Zawahiri has publicly designated the al Nusra Front as al Qaeda's official Syrian branch and ordered ISIL to limit its activity to Iraq.
More than 120,000 people have died in Syria since March 2011, when Assad's brutal repression of pro-democracy protests ignited an armed conflict. EFE