 After Yazid's governor in the city, Ubayd Allah ibn Ziyad, was ousted in the aftermath of the caliph's death, the Azdi leader of the Azd–Rabi'a alliance, attempted to gain control of the city and was killed by members of the rival Banu Tamim, the other major faction of the Basran garrison.This precipitated hostilities between the two groups, which spread to Khurasan where troops from both factions were deployed.Al-Muhallab was unable to take up his assignment in Khurasan due to the opposition of the Basran troops, who pressed him to lead the campaign against the Azariqa, a Kharijite faction that threatened the city.