The 1929 Palestine riots caused unrest in the Haganah ranks because the organization was not ready and did not respond appropriately to the Arab attacks. The disputes on this issue led to Tehomi's departure from the Haganah, and the establishment, in 1931, of the Haganah Bet, a parallel Zionist organisation that would later become the Irgun, which was more prepared to use violence, and which Tehomi headed. That same year, he left Palestine for the United States on private business, but when he stopped over at Piraeus, his visa was canceled by the US consul for medical reasons, and he returned to Palestine. Tehomi later tried to reunite the two organizations and in 1937 returned to the Haganah in order to take up a senior position. However, approximately only half of the 3,000 fighters of the Irgun followed Tehomi back into the Haganah. The other half retained the Irgun as a separate fighting organization, engaging in conflict with both British and Arabs in Palestine. When the Haganah failed to fulfill its obligations under the amalgamation agreement, Tehomi resigned, and from then on allegedly engaged in independent illegal immigration activities and intelligence work. Several years later he retired from all activity.