Hundreds of thousands of Holocaust survivors were being held in Displaced Persons Camp (DP Camps) aching to go to Mandatory Palestine. The British received much international pressure, specifically from U.S. president Harry Truman, to change their policy on immigration. Despite Britain's dependence on American economic aid, the British refused, claiming that they were experiencing too much resistance from the Arabs and Jews already in Palestine and feared what would happen if more were allowed to enter. The refusal to remove the white paper policy angered and radicalized the Yishuv. The Yishuv's militia groups set out to sabotage the British infrastructure in Palestine and continue in their illegal immigration efforts. In 1946, the British responded to the Yishuv's efforts and began a two-week search for Jews suspected of anti-British activities, arresting many of the Haganah's leaders. While the British were busy looking for the Haganah, the Irgun and Lehi carried out attacks on British forces. The most famous of their attacks was on the King David Hotel, the site of the British military command and the British Criminal Investigation Division. This location was chosen because a few weeks before a large quantity of documents was confiscated from the Haganah and brought there. Despite being warned by the Yishuv and told to evacuate the building the British officials decided not to cave in to the pressure. The Yishuv attacked anyway, resulting in 91 deaths, 28 of who were British and 17 who were Palestinian Jews.