BEIRUT (AP) -- Two suicide bombers killed a senior al Qaeda operative on Sunday, blowing themselves up inside the militant leader's compound in the northern Syrian city of Aleppo, rebels and activists said.
Abu Khaled al-Suri was the representative of al Qaeda chief Ayman al-Zawahri in Syria, rebels said. He was also a co-founder of Ahrar al-Sham, a powerful, hard-line Syrian rebel group seeking the overthrow of President Bashar Assad.
The group, alongside other Syrian rebel brigades, has been embroiled in infighting against a breakaway al Qaeda group, the Islamic State of Iraq and the Levant, in the middle of Syria's brutal three-year-old civil war.
"Sheik Abu Khaled al-Suri was the biggest figure in global jihad," said Akram al-Halabi, spokesman for the Islamic Front, a loose coalition of Islamic-oriented rebel groups, including Ahrar al-Sham. "He was appointed by Sheik Ayman al-Zawahri to mediate," al-Halabi said, speaking to The Associated Press via Skype.
Al-Souri's killing will further complicate efforts to resolve weeks of infighting between rebels and militants of the breakaway al Qaeda group, the Islamic State in Iraq and the Levant. The fighting has killed thousands since January. It has also badly weakened rebel ranks, allowing Assad-loyal forces to advance into key-rebel areas, including around Aleppo.
Rebels believe the Islamic State was behind the bombing that killed al-Suri, al-Halabi said. Weeks ago, he wrote a letter criticizing the rouge al Qaeda group, al-Halabi added.
"The first fingers of blame point to The State," said al-Halabi. "Unfortunately this is going to make the infighting worse."
The Britain-based Syrian Observatory for Human Rights said two others were also killed in the attack, which it attributed to the Islamic State. The Observatory obtains its information from a network of activists on the ground.
Al-Souri's activities in Syria were a chief reason why the U.S. and other Western allies held back on providing heavy weapons to rebels seeking Assad's overthrow, said analyst Charles Lister.
His presence in Ahrar al-Sham nearly led the U.S. to declare it a terrorist group.
"He is essentially a core al Qaeda veteran who almost certainly...had extensive, close relations with (Osama) bin Laden," and other senior leaders, Lister said. "The fact that he had such a high position in Ahrar al-Sham, and confirmed it himself, his al Qaeda history - it made elements in the U.S. administration potentially consider Ahrar al-Sham as a terrorist organization."
In 2002, Spanish officials described al-Suri, whose real name is Mohamed Bahaiah, as bin Laden's courier between Afghanistan and Europe.
Also Sunday, a car bomb exploded near a charity field hospital close to the Turkish border, wounding mostly medics and patients who had fled violence elsewhere in the country, activists and Turkish media said.
Turkish ambulance crews evacuated at least 11 of the wounded, including a five-month-old baby, to Turkey, said Syrian activists of the Idlib News group.
Zidane Zenglow, a journalist working for the pan-Arab al-Arabiya network, said at least one person was killed in the blast - a young girl, his cousin.
A video uploaded to YouTube showed what the narrators said was the burnt corpse of a small boy. Another showed people standing around a large smoldering vehicle as an ambulance wailed in the background. The videos were consistent with The Associated Press' reporting of the event.