The United States says it will hold the Syrian regime accountable for a chemical weapons attack that has shocked 'the conscience of the world'.
Several hundred people were killed in the poison gas attack near Damascus last week.
UN inspectors were finally allowed to access the scene yesterday - but came under sniper fire.
Western leaders are now weighing their options - with British Prime Minister David Cameron facing calls to recall parliament to discuss the crisis.
The Assad regime is denying all responsibility for the chemical weapons attack - but US Secretary of State John Kerry says they lack credibility.
