European Jews fleeing from anti-Semitic violence (especially Russian pogroms) immigrated in increasing numbers to Palestine. When the British restricted Jewish immigration to the region (see White Paper of 1939), Jewish immigrants began to use guerrilla warfare against the British for two purposes: to bring in more Jewish refugees, and to turn the tide of British sentiment at home. Jewish groups such as the Lehi and the Irgun – many of whom had experience in the Warsaw Ghetto battles against the Nazis, fought British soldiers whenever they could, including the bombing of the King David Hotel. They also conducted attacks against the Arabs, and prepared the infrastructure for the coming 1948 conflict.