Shi'ite Islam

While Sunni Muslims recognized the first four caliphs as the Prophet Mohammed's legitimate successors, the followers of the Shii (or Shi'a) branch of Islam place authority solely in the hands of the fourth caliph, Ali, and his descendants. The Shi'ites accept some of the Hadith (books that supplement the Koran) that the Sunnis accept, but not all of them. The Shi'ites also have some Hadith of their own.

The Sunni-Shii split occurred in the decades following the death of the prophet Mohammed. The two branches have a long history of tension and rivalry. Their differences lie mainly in methods of leadership.

Shi'ism is the official religion in Iran. Other countries where Shi'ites are in the majority include Iraq, Bahrain and Lebanon. Many other countries have Shii minorities, including Pakistan and Afghanistan.

Afghanistan's Shi'ites primarily come from the Hazara ethnic group, located in the northwestern part of the country near the Iranian border.