The majority of the population belongs to the Bantu-speaking Hadimu ethnic group. Other ethnic groups include the Tumbatu (who live on Tumbatu and in the northern part of Zanzibar) and migrants from the E African mainland and from the Comoros Islands. In addition, a small percentage of the inhabitants is of Arab and Persian descent and some are of South Asian background. Most Zanzibaris are Sunni Muslims; some follow traditional beliefs, and there are also small numbers of Christians and Hindus. Swahili is predominantly spoken. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved. See more Encyclopedia articles on: Tanzania Political Geography