If I recall, the Serbs were killed in the millions by the Croatian Ustashis and Bosnian Muslims, who both collaborated with the Nazis. There were two Muslim SS divisions setup by SS leader Heinrich Himmler, a friend and admirer of Islam. The Ustashis and Hanjar SS were very barbaric and brutal. Sadly, many Ustashis never saw justice and fled to Argentina with the help of Juan and Evita Peron. The Hanjar SS division fled to Egypt, Syria, Saudi Arabia, and Iraq.
I just read "The Rise and Fall of the Third Reich" by Shirer which only touched on the muzzie connection. It didn't go into detail on it though. Can you point me to a book on it? I have an idea about how deep that connection was, but I'd like to know alot more about it.
Slavs were definitely a favorite target of the Nazis.
Anyway, I'm not sure about the specific outcome of the incident or the collaboration of Bosniaks, but I do know that Himmler was indeed a critic of "soft" Christianity and praised Islam for its masculinity and martiality. I also know that Hitler romanticized it enough to ally with the Persians--the original Aryans (hence the name "Iran": "land of the Aryans").
But back to Serbia. I do know that in the fascist Independent State of Croatia (which was actually a puppet state for the Axis powers, who occupied the country and then propped up the Ustae movement), Slavko Kvaternik demonized the Serbs because of their repressive Yugoslav king. Also, at the time, its boundaries included what is now Bosnia. I don't know what was up with the Bosniaks, but I do know that the Ustae envisioned the following plan: kill 1/3 of the Serbs, "convert" another 1/3 to Roman Catholicism [at gunpoint], and expel the rest. Not sure how far they got on this before we went in and kicked their *ss*s.