In April 1936, the Arab High Command formed, led by Mufti Haj Amin al-Husseini, and called for a general strike of Arab workers and a boycott of Jewish products. These actions swiftly escalated into terrorist attacks against the Jews and the British. This first stage of the "Arab Revolt" lasted until November 1936. The second stage began in September 1937, shortly after the Peel Commission recommended the partition of Palestine. In this second phase, clashes with the British forces became much more severe, as did the attacks on Jewish settlements.
Sources: Library of Congress