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 Haganah's 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. Irgun's best-known attack targeted the King David Hotel in Jerusalem, parts of which housed the headquarters of the British civil and military administrations. The bombing, in 1946, killed ninety-one people and injured forty-six, making it the most deadly attack during the Mandate era. This attack was sharply condemned by the organized leadership of the Yishuv, and further widened the gulf between David Ben-Gurion's Hagana and Begin's Irgun. Following the bombing, Ben-Gurion called Irgun an "enemy of the Jewish people". After the founding of the state of Israel in 1948, Menachem Begin (Irgun leader from 1943 to 1948) transformed the group into the political party Herut, which later became part of Likud in an alliance with the center-right Gahal, Liberal Party, Free Centre, National List, and Movement for Greater Israel. On the 60th anniversary of the bombing, a plaque was unveiled at the hotel.