Conflict between Palestinian nationalists and various types of pan-Arabists continued during the British Mandate, but the latter became increasingly marginalized. Two prominent leaders of the Palestinian nationalists were Mohammad Amin al-Husayni, Grand Mufti of Jerusalem, appointed by the British, and Izz ad-Din al-Qassam. After the killing of sheikh Izz ad-Din al-Qassam by the British in 1935, his followers initiated the 1936–39 Arab revolt in Palestine, which began with a general strike in Jaffa and attacks on Jewish and British installations in Nablus. The Arab Higher Committee called for a nationwide general strike, non-payment of taxes, and the closure of municipal governments, and demanded an end to Jewish immigration and a ban of the sale of land to Jews. By the end of 1936, the movement had become a national revolt, and resistance grew during 1937 and 1938. In response, the British declared martial law, dissolved the Arab High Committee and arrested officials from the Supreme Muslim Council who were behind the revolt. By 1939, 5,000 Arabs had been killed in British attempts to quash the revolt; more than 15,000 were wounded.