Rivalry between jihadist groups fighting in Syria has sharply divided global militant ranks once loosely allied under al-Qaeda, sparking infighting which experts say has hampered efforts to topple Syrian President Bashar al-Assad.
While senior leaders of al-Qaeda were all but above question under founder Osama bin Laden, the conflict has gone so far that even his replacement, Ayman al-Zawahiri, has come in for fierce criticism on jihadist forums online.
Powerful rebel groups in Syria, including al-Qaeda’s designated local affiliate al-Nusra Front, have been locked in fierce fighting with jihadist group the Islamic State of Iraq and the Levant (ISIL), with thousands of people killed since January.
Jihadists were initially welcomed by other rebels battling to topple al-Assad since 2011.
However, allegations of brutal abuses against civilians and rival fighters sparked a backlash and even accusations that they served al-Assad’s interests.
In a sign of how sharp the divisions have become, ISIL spokesman Abu Mohammed al-Adnani has accused al-Qaeda leaders of betraying the jihadist cause.
“Al-Qaeda today is no longer a base of jihad,” Adnani said in a statement posted on jihadist forums, playing off the militant group’s name, which means “the base” in Arabic.
“Its leadership has become a hammer to break the project of the Islamic State,” Adnani said, adding that “the leaders of al-Qaeda have deviated from the correct path.”
“They have divided the ranks of the mujahidin [holy warriors] in every place,” he said.
Online, the clash among jihadists has seen criticism of Zawahiri from around the Islamic world, though others have defended the al-Qaeda chief.
“Zawahiri has fallen... We will not listen to him any more. To the dustbin of history, oh al-Qaeda,” tweeted ISIL supporter Munassar al-Mumineen.
A visiting fellow at the Brookings Doha Center, Charles Lister, said the dispute is ultimately over leadership of the jihadist movement.
“This division has become more about the fight to represent the true jihadist movement, both in Syria but also internationally,” Lister said.
“This continuing battle for influence between al-Nusra and ISIL has the potential to cause shock waves across the international jihadist community... The conflict in Syria has provided an enormous opportunity for jihadist groups and with such a significant opportunity comes the possibility of divisions,” he added.