This is not the act of warriors. This is barbarism.
Proof of this. Here is a video clearly made by Muslims bragging of their slaughter. Specifically bragging of killing Christians I might add. Check the last minute.
“The secret of all victory lies in the organization of the non-obvious.” -Marcus Aurelius
Welcome to the African wars, both sides will commit atrocities that will turn your stomach.
Unfortunately the only way to stop the barbarians (without killing all of them) is to prove to them that you are capable of even worse barbaric behavior then they are. God help us and save us from what is coming.