The Hebron massacre refers to the killing of sixty-seven Jews on 23 and 24 August 1929 in Hebron, then part of the British Mandate of Palestine, by Arabs incited to violence by rumors that Jews were massacring Arabs[1] in Jerusalem and seizing control of Muslim holy places. This massacre, together with that of Safed, sent shock waves through Jewish communities in Palestine and across the world.
67 Jews were killed and Jewish homes and synagogues were ransacked; nineteen local Arab families saved 435 Jews by hiding them in their houses at great risk to themselves.[2][3] The survivors were evacuated from Hebron by the British authorities. Many returned in 1931, but almost all left again during 1936–1939.[4] It also led to the re-organization and development of the Jewish paramilitary organization, the Haganah, which later became the nucleus of the Israel Defense Forces.

http://en.wikipedia.org/wiki/1929_Hebron_massacre