A US intelligence report Friday blamed Syria's government for a chemical weapons attack with "high confidence" and said it was "highly unlikely" the outrage was a ruse plotted by rebels.
The report said that 1,429 people were killed in the attack, including 426 children, and said the assessment was based on "multiple" streams of intelligence.
"The United States Government assesses with high confidence that the Syrian government carried out a chemical weapons attack in the Damascus suburbs on August 21, 2013," the report, released by the White House said.
"We further assess that the regime used a nerve agent in the attack."
The report went on to detail casualty figures from the attack on a Damascus suburb on August 21, and said they would likely rise as new intelligence comes in.
"A preliminary US government assessment determined that 1,429 people were killed in the chemical weapons attack, including at least 426 children."
The unclassified assessment, which omitted sourcing and raw intelligence to protect US intelligence assets, also debunked the theory, advanced notably by Russia, that opposition forces could have carried out the attack.
"We assess that the scenario in which the opposition executed the attack on August 21 is highly unlikely."
"The body of information used to make this assessment includes intelligence pertaining to the regime's preparations for this attack and its means of delivery, multiple streams of intelligence about the attack itself and its effect, our post-attack observations, and the differences between the capabilities of the regime and the opposition.
"Our high confidence assessment is the strongest position that the US Intelligence Community can take short of confirmation."