“I ask and demand that the president of the United States, Barack Obama, as the head of the country that has the strongest presence in the international community, takes personal responsibility for what has happened.”

For now, Western governments want confirmation that chemical weapons have been used. Meguerditch Terzian of the international relief group Doctors Without Borders is convinced that some form of neurotoxin was released in Syria.

“If there is a massive arrival of patients within a short period of time from the same location with neurotoxic symptoms, with a lot of deaths, it means that a serious neurotoxic agent has been used in Damascus recently,” said Terzian.

Evidence of chemical weapons use has been widely condemned, including by one of Syria’s staunchest allies, Iran.