 Complete the following phrase:  Following the 1929 Hebron massacre of 67 Jews in the Mandate of Palestine, the Zionist militia Haganah transformed itself into a paramilitary force. In 1931, however, the more militant Irgun broke away from Haganah, objecting to Haganahs policy of restraint. Founded by Avraham Tehomi, Irgun sought to aggressively defend Jews from Arab attacks. Its tactic of attacking Arab communities, including the bombing of a crowded Arab market, is considered among the first examples of terrorism directed against civilians. After the British published the White Paper of 1939, which placed strict restrictions on Jewish immigration into Palestine which was seen as unacceptable to Zionist groups, the Irgun began a campaign against the British authorities by assassinating police, capturing British government buildings and arms, and sabotaging railways. Irguns best-known attack targeted the 