The purported casus belli was the defection of the 32nd Division, part of Ahrar al-Sham's eastern branch, from the Levant Front-dominated Third Legion of the SNA. Following this defection, the Levant Front, including reinforcements of tanks and artillery from Azaz city,[2] attacked Ahrar al-Sham positions in the al-Bab District countryside on 18 June,[2] besieging the Ahrar al-Sham-held Kurdish-majority villages of Tel Battel and Abla before proceeding to storm and capture Ahrar al-Sham's headquarters in the villages. The two fighting factions then withdrew to the outskirts of the villages.[3] At least one Ahrar al-Sham fighter was killed,[9] and four civilians, including two children, were killed, and 11 civilians wounded during the clashes in the al-Bab countryside, which had spread to the villages of Sousian, al-Hadath,[8] Alwan, and Sheikh Alwan.[2]