1517 Hebron attacks occurred in the final phases of the 1513–17 Ottoman–Mamluk War, when Turkish Ottomans had ousted the Mamluks and taken Palestine. The massacre targeted the Jewish population of the city but the exact amount of casualites is unknown.
 

An account of the event, recorded by Japheth ben Manasseh in 1518, mentions how the onslaught was initiated by Turkish troops led by Murad Bey, the deputy of the Sultan from Jerusalem. Jews were attacked, beaten and many were killed as their homes and businesses were looted and pillaged. It has been suggested that the stable financial position of the Hebronite Jews at the time was what attracted the Turkish soldiers to engage in the mass plunder. Others suggest the pogrom could have in fact taken place in the midst of a localized conflict, an uprising by the Arabs against the new Ottoman rulers. Those who survived the calamity fled to Beirut and Jews only returned to Hebron 16 years later in 1533.
 

Note: At time of this writing the exact amount of Niftarim of the Cause is unknown.
 

Sources
https://en.wikipedia.org/wiki/1517_Hebron_attacks