ISIL has selected Saudis as military leaders for the skirmishes with the Kurds, a source said, al-Hayat daily reported.
The majority of people killed in the fights were Saudi but there were Iraqis and Syrians among the dead as well.
A Syrian human rights activist, who preferred anonymity, said all military leaders of most cities and towns are Saudis selected by the terrorist group.
The source noted that Saudis speak standard Arabic in order not to give away their accent and identity.
However, most Syrians can recognize the Saudi accent, the source said. He believed the majority of people who carried out these attacks were young Saudis.
Al-Hayat published a report earlier about young Saudis who blew themselves up in different places in Syria.
The reason behind this is that the Saudis gained experience in fighting when they were members of al-Qaeda terrorist group.
It is Saudis who speak for ISIL and recruit new members for the organization, according to the source.