On 21 August 2013 two opposition-controlled areas in the suburbs around Damascus, Syria were struck by rockets containing the chemical agent sarin. Estimates of those killed by the attack ranged from 281 to 1,729. The attack was the deadliest use of chemical weapons since the Iran-Iraq War. Following an inspection by a UN investigation team confirmed clear and convincing evidence of the use of sarin delivered by surface-to-surface rockets, a 2014 report by the UN Human Rights Council found that significant quantities of sarin were used in a well-planned indiscriminate attack targeting civilian-inhabited areas, ... The evidence available concerning the nature, quality and quantity of the agents used on 21 August indicated that the perpetrators likely had access to the chemical weapons stockpile of the Syrian military, as well as the expertise and equipment necessary to manipulate safely large amount of chemical agents. Based on the trajectories calculated by the UN mission, Human Rights Watch states that the missiles were launched from a large military base on Mount Qasioun which is home to the Republican Guard 104th Brigade.