US, UK and France say UN report blames Bashar al-Assad

The US and UK ambassadors to the United Nations said technical details of a UN report showed that only the regime could have been responsible for the 21 August attack.

However, Russia said claims that the rebels were responsible could not be shrugged off.

The report said sarin-filled rockets were fired. UN Secretary General Ban Ki-moon described it as a despicable crime.

The attack led the US to threaten military action against Syria.

This sparked a diplomatic dialogue between the US and Russia, which in turn led to an agreement under which Syria has agreed to make safe its chemical weapons.

The UN report did not attribute blame for the attack, as that was not part of its remit.

Ban Ki-moon was asked at a news conference whether he knew who was behind the attack, but he replied that "we may all have our own thoughts" but it was for "others to decide" what steps should be taken to bring those responsible to justice.

UK Foreign Secretary William Hague said that from the wealth of technical detail in the report - including on the scale of the attack, the consistency of sample test results from separate laboratories, witness statements, and information on the munitions used and their trajectories - it was abundantly clear that the Syrian regime was the only party that could have been responsible.

US ambassador to the UN Samantha Power used similar language when saying that technical details of the UN report make it clear that only Bashar al-Assad’s regime could have carried out this large-scale chemical weapons attack.

She also pointed out that the 122mm rockets cited in the report were of the type previously associated with government forces and that the quality of the sarin was higher than that used by Saddam Hussein in Iraq.

French Foreign Minister Laurent Fabius said: "When you look at the findings carefully, the quantities of toxic gas used, the complexity of the mixes, the nature, and the trajectory of the carriers, it leaves absolutely no doubt as to the origin of the attack."

Fabius is travelling to Moscow on Tuesday for negotiations over a possible UN Security Council resolution on the agreement to place Syria's chemical arsenal under international control.