Greek Jews: The Cham Albanians collobarated with Nazis

During World War II, when Greece was occupied by the Axis, 86% of the Greek Jews, especially those in the areas occupied by Nazi Germany and Bulgaria, were murdered despite efforts by the Greek Orthodox Church and many Christian Greeks to shelter Jews. Although the Germans and Bulgarians deported a great number of Greek Jews, many were hidden by their Greek neighbours. Despite this though, roughly 49,000 Jews were deported from Thessaloniki alone and exterminated.
Muslim Cham Albanians collobarated with Nazis and played an active part in the Holocaust in Greece, including the round-up and expulsion to Auschwitz and Birkenau of the 2,000 strong Romaniotes Greek-Jewish community of Ioannina in April 1944 [1]
The Romaniotes were protected by the Greek government until the Nazi occupation. During the occupation the Romaniotes could use the Greek language better and more efficiently than the Sephardim, who spoke Ladino and whose Greek had a distinct, "singing" accent. That made the Sephardim more vulnerable as targets, and was one of the many factors that led to such great losses among Sephardic communities. In Ioannina 1860 out of 1950 Jews were deported to Auschwitz and Birkenau in April 1944. Most of them were exterminated by the Nazis.