On 15 March, rebels seized control of an ammunition factory complex and munitions depots in the town of Khan Tuman, southwest of Aleppo. The complex had been used to supply the Army with munitions to regularly shell rebel positions in the surrounding area. On 19 March there was a chemical attack in Khan al-Assal, about 15 kilometers west of Aleppo, with about 26 fatalities. It was the first widely reported use of chemical weapons in the war. Both the government and rebels claim that a missile or rocket was used to deliver the agent. The Syrian Information Minister blamed the rebels for the attack, while the rebels blamed the government. On the night of 29 March, the opposition Aleppo Media Center claimed that rebel forces had captured Sheikh Maqsoud, which was previously held by both government and Kurdish forces. However, SOHR stated that while rebel forces advanced into the district, they had captured only the eastern part. SOHR also reported that heavy fighting was still ongoing. It was also confirmed that during their advance, rebels had captured and killed the top pro-government Sunni cleric in the district, Hassan Seifeddine. Reports by pro-government Al-Ikhbariya TV and SANA stated he was beheaded and his head was placed on the minaret of the Al-Hassan Mosque. SOHR confirmed that his body had been dragged and paraded in the neighborhood. On 31 March, government troops counterattacked. Fighting was concentrated by the Awarded bridge and in the area between eastern Sheikh Maqsoud and the Bustan al-Basha neighborhood. Since the rebel attack on the district started, 43 people had been killed, including 15 civilians, 19 government soldiers and militiamen and 9 rebels. It was claimed by YPG fighters in Sheikh Maqsoud that following a long discussion within the group, the (mostly Kurdish) YPG decided to end their neutrality in Aleppo and switch to the rebel side, cooperating with the FSA in their advance through the district where several pro-government militias and intelligence officers were located. However, a day later, a YPG political representative denied the claim and stated that the Kurds had not aligned with the rebels, instead that Kurdish forces fought government troops after the Army attempted to reach Arab parts of the district that had been captured by opposition forces, via the Kurdish areas. According to the YPG, as a result of these clashes, which also included artillery, 15 Syrian soldiers and one YPG fighter, YPG military council member Zekeriya Xelîl, were killed. On 2 April, clashes erupted in the strategic village of Aziza, on the southern outskirts, from which rebels were launching attacks against Aleppo international airport and the adjacent military air base.