When Britain ruled Malaya, drastic socio-economic changes took place in the country and the changes had a strong impact on other states outside the union including Kelantan and Terengganu. An important change was the influx of foreign workers, particularly Chinese and Indians who gained economic advantage by working in mines and on rubber plantations. Capitalism enabled the Chinese and Indian ethnic groups to become the middle class while the indigenous Malays led a less developed economic life and became the poorest class. Ultimately, they were economically the underclass. This economic difference between the Malays and the Chinese in particular was the beginning of racial conflict and the conflict became stronger when more Chinese and Indians migrated to the country and settled down permanently. The Malays demanded equal socio-political status by using cultural and religious levers against the Chinese who had more economic power in their states. Strict religious adherence to Islam was the example that Muslim Malays in other states used as a tool against the economic dominance of the Chinese.