Syria: inspectors say sarin used as Ban Ki-moon says gas attacks were 'war crime' - Telegraph.co.uk

The UN experts' report will now become a key weapon in a Security Council battle over what degree of threat should be made against Assad to make him disarm.

The UN inspectors, led by Prof Ake Sellstrom, were in Damascus when the attacks took place. They visited three suburbs and concluded that all suffered bombardment by "surface-to-surface rockets containing the nerve agent sarin".

The "clear and convincing evidence" came in the form of "environmental, chemical and medical samples" along with interviews with 50 survivors. These eyewitnesses reported "an attack with shelling" followed by the onset of symptoms ranging from blurred vision to vomiting and loss of consciousness. They described how many people were simply incapacitated, found "lying on the ground" either "deceased or unconscious".

Many had been asleep when the rockets fell between 2am and 5am, dispersing their toxic cargo. Local weather conditions, with temperatures falling, made the attacks still more deadly. Instead of rising into the sky, the gas stayed "close to the ground" and penetrated "lower levels of buildings", including the basements where people often slept for shelter.

The UN mission did not compile a death toll, saying only that the "relatively large scale" attack happened "against civilians, including children". In all, the experts visited the locations where five rockets had exploded.

As for the weapons involved, the experts identified two types of artillery-launched rocket: the M14 and the 330mm. Both are in the armoury of Mr Assad's forces, which also possesses one of the world's biggest stockpiles of sarin nerve gas.

Whether the rebels have captured these delivery systems - along with sarin gas - from government armouries is unknown. Even if they have, experts said that operating these weapons successfully would be exceptionally difficult.

"It's hard to say with certainty that the rebels don't have access to these delivery systems. But even if they do, using them in such a way as to ensure that the attack was successful is the bit the rebels won't know how to do," said Dina Esfandiary, an expert on chemical weapons at the International Institute for Strategic Studies.

The investigators had enough evidence to trace the trajectories followed by two of the five rockets. If the data they provide is enough to pinpoint the locations from which the weapons were launched, this should help to settle the question of responsibility.

John Kerry, the US secretary of state, says the rockets were fired from areas of Damascus under the regime's control, a claim that strongly implicates Mr Assad's forces.