Islam is the largest religion in Sudan, and Muslims have dominated national government institutions since independence in 1956. According to UNDP Sudan, the Muslim population is 97%, including numerous Arab and non-Arab groups. The remaining 3 scribe to either Christianity or traditional animist religions. Muslims predominate in all but Nuba Mountains region. The vast majority of Muslims in Sudan adhere to Sunni Islam of Maliki school of jurisprudence, deeply influenced with Sufism, making Sudan one of the most tolerant Muslim majority countries in the world. There are also some Shia communities in Khartoum, the capital. The most significant divisions occur along the lines of the Sufi brotherhoods. Two popular brotherhoods, the Ansar and the Khatmia, are associated with the opposition Umma and Democratic Unionist Parties respectively.