A deal to evacuate ISIS fighters and other militants was halted Saturday one day after the death of powerful Syrian rebel chief Zahran Alloush, who was killed in an airstrike claimed by the government. Hezbollah's Al-Manar reported that buses evacuating fighters and their families from besieged southern Damascus towns to other rebel-held areas ceased transportation after the assassination of Alloush, the commander of the Jaish al-Islam (Army of Islam) movement, who was part of the agreement. "ISIS fighters and other faction militants stopped leaving the Hajar al-Aswad area," the channel said. It cited sources saying that Alloush "was part of the deal to facilitate the evacuation of gunmen (from south Damascus) and their transportation to the northern cities of Raqa" which is held by ISIS. However, the channel didn't give any further details. The Jaish al-Islam (Army of Islam) movement is the predominant opposition faction in the Eastern Ghouta rebel bastion east of Damascus. Al-Manar had reported Friday that 18 buses, accompanied by United Nations vehicles and Syrian government security personnel, had headed to besieged southern Damascus areas to transfer ISIS and Al-Qaeda-Affiliate Nusra Front rebels to areas in Bir al-Qasab in Reef Dimashq after laying down their heavy arms and ammunition. It added that "3,567 people, including 2,000 rebel gunmen," were to leave the areas of Hajar al-Aswad, Qadam, Asali and some of the Yarmuk camp neighborhoods. Militants from ISIS and its rival Nusra Front agreed to leave the areas as part of a landmark ceasefire. They were supposed to be transported to the northern cities of Raqa, held by ISIS, and Marea which is controlled by Islamists and Nusra groups. The three southern districts have been under a crippling government siege for more than two years. ISIS militants attacked the Yarmuk Palestinian camp in April, battling Nusra units for control. The extremists then overran parts of Qadam in August after launching an attack from their base in nearby Hajar al-Aswad. Their advance into Qadam brought them closer than ever to central Damascus. A similar deal earlier this month in the central city of Homs saw 2,000 rebels and civilians leave the last opposition-held neighborhood.