Islam
The Shi'ites believe that just as only God can appoint a prophet, he can appoint a second leader after the prophet. Shi'a Muslims believe that God chose Ali as the leader after Muhammad. About 10-20% of Muslims are Shi'a which means that there are about 120 million world wide. Shi'a Muslims form the majority of Muslims in Iran, Azerbaijan, Bahrain, Iraq, and Lebanon. The largest adhab in Yemen is Zaydi Shia. Shias commonly gather for Day of Ashura in Karbala. They accept four hadiths.