The Syrian ambassador to the United Nations claimed that the chemical attacks in Damascus were carried out by terrorist groups, and not by Bashar Assad's regime.
Bashar Jaafari told a news conference at the UN in New York that the country's own soldiers had been infected by inhaling the poisonous gas, believed to be sarin.
He said he had sent a letter of request from the Syrian government to the UN Secretary General Ban Ki-moon to investigate the "heinous attacks".
The prospect of a US and UK military intervention in Syria appears increasingly likely, but what would an attack by western forces involve?
A textile factory in Damascus has started producing gas masks in case of a repeat of a suspected chemical attack on the area.
Western countries including the UK are considering their response to Syria as evidence of a large-scale chemical attack in Damascus mounts.