of 5 June, and was only thrown back with great difficulty, with al-Mansur himself reportedly rallying the defenders. The two armies remained entrenched around Kairouan for the next two months, engaging in frequent clashes. Abu Yazid tried several times to take the city gates by assault, but al-Mansur had established smaller fortified camps to protect them. Abu Yazid tried to force the Fatimids to withdraw by sending his son to raid the environs of al-Mahdiya, where many of the Kutama had settled their families; but although al-Mansur sent some troops to shield them, he refused to move his main army. While al-Mansur was slowly building up his numerically inferior forces with contingents from the remote provinces of the Fatimid empire, Abu Yazid's support began to dwindle as his followers abandoned his camp; only the Hawwara and Banu Kamlan Berbers remained steadfastly loyal to him. With increasing confidence, al-Mansur marched his army out to provoke a pitched battle, but Abu Yazid refused. Finally, on 13 August the Fatimids stormed the rebel camp, and Abu Yazid with his troops broke and fled. The victory proved doubly fortuitous for al-Mansur, as an Umayyad fleet, dispatched to assist Abu Yazid, turned back after reaching Ténès, when its commander heard news of the Fatimid victory at Kairouan. In the meantime, al-Hasan al-Kalbi gathered his Kutama at Constantine, and recaptured Béja and Tunis. With Abu Yazid in retreat, he now joined his forces with al-Mansur's army. Pursuit by al-Mansur On 24 October, al-Mansur left Kairouan in pursuit of the retreating Abu Yazid. By early December, the Fatimid caliph recovered Marmajanna, Béja, Billizma, Tubna (ancient Tubunae), and Biskra. The Fatimids were greeted as liberators by the locals, and received the submission of Ibn Hazar, the leader of the Zenata Berbers, and the governor of Msila and the Zab region, Ja'far ibn Ali ibn Hamdun. With the lands of the Zenata now barred to him, Abu Yazid turned south to bypass them through the desert. Al-Mansur tried to follow him, but at Biskra he was forced to stop, as the local guides warned him that the route followed by the Kharijite leader and his followers was extremely dangerous. After crossing the desert, Abu Yazid established himself in the Jabal Salat mountains, west of the Chott el Hodna lake. As a result, the Fatimid army turned back from Biskra to Tubna, and thence marched west, along the northern shore