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 descent and some are of Indian or Pakistani background. Most Zanzibaris are Sunni Muslims; some follow traditional beliefs, and there are also small numbers of Christians and Hindus. Swahili is predominantly spoken.