In its initial stages, the rebellion was limited to the region around the city of Basra and the Blind Tigris. Early efforts by the Abbasid government to crush the revolt proved ineffectual, and several towns and villages were occupied or sacked, including al-Ubulla in 870 and Suq al-Ahwaz in 871. Basra fell in September 871 following an extended blockade, resulting in the city being burned and its inhabitants massacred. A retaliatory campaign undertaken by the caliphal regent Abu Ahmad ibn al-Mutawakkil (known by his honorific of al-Muwaffaq) against the rebels in 872 ended in failure, and the Zanj remained on the offensive over the next several years.