The 46 tribal fighters ISIS executed earlier this week in Hit were just a drop in the bucket, as mass graves have been discovered now showing that at least 228 fighters from the Albu Nimr tribe were killed by ISIS recently.

The Albu Nimr tribe, in the eastern portion of Anbar Province, had been one of the driven forces behind the “Awakening” fighters during the US occupation, and have been one of the few tribes resisting the ISIS takeover.

ISIS routed the fighters, and are keen to make an example of them, hoping to discourage other tribal factions from backing any Iraqi government rebellion.

The US seems keen to fuel an uprising against ISIS in Anbar, and General Martin Dempsey is pushing Iraq to start funneling weapons to the various tribes in hopes of starting them resisting more seriously.

ISIS has tried to manage tribal relations very carefully to prevent such unrest erupting, though in the few times when it’s happened they’ve killed massive numbers of fighters, ensuring that the tribes who do resist once aren’t around to resist again.