This report details two alleged chemical weapons attacks in Syria on the opposition-controlled Damascus suburbs of Eastern and Western Ghouta, located 16 kilometers apart, on the morning of August 21, 2013. The attacks killed hundreds of civilians, including large numbers of children. Human Rights Watch analyzed witness accounts of the rocket attacks, information on the likely source of the attacks, the physical remnants of the weapon systems used, and the medical symptoms exhibited by the victims of the attack as documented by medical staff.
Our investigation finds that the August 21 attacks were likely chemical weapons attacks using a surface-to-surface rocket system of approximately 330mm in diameter—likely Syrian-produced—and a Soviet-era 140mm surface-to-surface rocket system to deliver a nerve agent. Evidence suggests the agent was most likely Sarin or a similar weapons-grade nerve agent. Three local doctors told Human Rights Watch that victims of the attacks showed symptoms which are consistent with exposure to nerve gas, including suffocation; constricted, irregular, and infrequent breathing; involuntary muscle spasms; nausea; frothing at the mouth; fluid coming out of noses and eyes; convulsing; dizziness; blurred vision; and red and irritated eyes, and pin-point pupils.
The evidence concerning the type of rockets and launchers used in these attacks strongly suggests that these are weapon systems known and documented to be only in the possession of, and used by, Syrian government armed forces. Human Rights Watch and arms experts monitoring the use of weaponry in Syria have not documented Syrian opposition forces to be in the possession of the 140mm and 330mm rockets used in the attack, or their associated launchers.
The Syrian government has denied its responsibility for the attack, and has blamed opposition groups, but has presented no evidence to back up its claims. Based on the available evidence, Human Rights Watch finds that Syrian government forces were almost certainly responsible for the August 21 attacks, and that a weapons-grade nerve agent was delivered during the attack using specially designed rocket delivery systems. The scale and coordinated nature of the two attacks; against opposition-held areas; the presence of government-controlled potential launching sites within range of the targets; the pattern of other recent alleged chemical weapon attacks against opposition-held areas using the same 330mm rocket delivery system; and the documented possession of the 140mm and 330mm rocket systems able to deliver chemical weapons in the government arsenal—all point towards Syrian government responsibility for the attacks.
Human Rights Watch has investigated alternative claims that opposition forces themselves were responsible for the August 21 attacks, and has found such claims lacking in credibility and inconsistent with the evidence found at the scene. Claims that the August 21 deaths were caused by an accidental explosion by opposition forces mishandling chemical weapons in their possession are inconsistent with large numbers of deaths at two locations 16 kilometers apart, and documentation of rocket attacks on the sites that morning, as evidenced by witness accounts, the damage visible on the rockets themselves, and their impact craters.