As part of the Arab opposition to the increasing Jewish presence in Mandatory Palestine, some Arab leaders sought to orchestrate anti-Jewish boycotts from 1922. The original boycott forswore any dealings with any Jewish-owned business operating in Mandatory Palestine. Palestinian Arabs "who were found to have broken the boycott ... were physically attacked by their brethren and their merchandise damaged" when Palestinian Arabs rioted in Jerusalem in 1929. Another, stricter boycott was imposed on Jewish businesses following the riots that called on all of Arabs in the region to abide by its terms. The Arab Executive Committee of the Syrian-Palestinian Congress called for a boycott of Jewish businesses in 1933, and in 1934 the Arab Labor Federation conducted a boycott as well as an organized picketing of Jewish businesses. In 1936, the Palestinian Arab leadership called on another boycott and threatened those who did not respect the boycott with violence. However, this boycott was unsuccessful as Jewish lawyers, physicians, and hospitals were too heavily integrated into Palestinian society.