In case you haven't noticed, 95% of their victims are sunni
They attack everybody, so this is a non-issue
These non muslims certainly do kill sunnis, but they seem to take excessive liking to killing shias more then any others. They have been doing exclusively horrible things to these people for the last few years. If you read the reports from parachanaar, or keep up with them, its nauseating: cutting off hands and other limbs of shia children and young men.