One of those, who goes by the name Hamood Almossa, says ISIS militants are divided into several competing groups: some are extreme hardliners originally attracted by the harsh application of Sharia law; others are Syrian militants who now complain that they bore the brunt of the months-long fighting over the border town of Kobani and are reluctant to be used to reinforce ISIS units in neighboring Iraq. Still others are Gulf Arabs jealous of the power held by hardcore Iraqi militants who form the inner coterie of the ISIS leadership around Abu Bakr al-Baghdadi. The Gulf Arabs, many of whom are veterans from the conflicts in Afghanistan and Pakistan, feel excluded from overall decision-making.

North African recruits among the Islamic State’s estimated 20,000 foreign fighters are among the most disgruntled, the Raqqa activists say. They complain they receive less than Gulf Arabs, Europeans and Chechens who are paid up to $1,000 a month. They grumble about missing out on many of the spoils of war, including women slaves and jihadi brides. Like local Syrian fighters, North African recruits say they have been used as cannon fodder, especially in the battle for Kobani.

Last week, four Tunisian recruits who joined ISIS months ago were executed in the neighborhood of Rumaila in central Raqqa, say opposition activists. They were described as traitors. Two other Tunisians, possibly along with family members, were executed in the Eddekhar neighborhood of Raqqa.

The quarrels and executions trigger more cycles of revenge as commanders and groups compete and jockey for power and survival.