United Nations weapons inspectors have confirmed that Sarin gas was used against civilians in Damascus last month.
The UN Secretary General Ban Ki Moon has briefed the Security Council on the inspectors' report.
It concludes that samples gathered provide convincing evidence that surface-to-surface rockets containing nerve gas were used in the Syrian capital on August the 21st.
However, the UN inspectors do not say who was responsible for the attack, which President Bashar Al Assad has denied - claiming that rebels were behind it.
It's believed up to 1400 people were killed in the atrocity.
Presenting the report's findings, the UN Secretary General described it as a "war crime".
