In protest against, and with the aim of ending Jewish immigration to Palestine, the Great Arab Revolt of 1936–1939 broke out on April 19, 1936. The riots took the form of attacks by Arab rioters ambushing main roads, bombing of roads and settlements as well as property and agriculture vandalism. In the beginning, the Irgun and the Haganah generally maintained a policy of restraint, apart from a few instances. Some expressed resentment at this policy, leading up internal unrest in the two organizations. The Irgun tended to retaliate more often, and sometimes Irgun members patrolled areas beyond their positions in order to encounter attackers ahead of time. However, there were differences of opinion regarding what to do in the Haganah, as well. Due to the joining of many Betar Youth members, Jabotinsky (founder of Betar) had a great deal of influence over Irgun policy. Nevertheless, Jabotinsky was of the opinion that for moral reasons violent retaliation was not to be undertaken.