Syria conflict: 'Chemical attacks kill hundreds'
21 August 2013 Last updated at 18:45 BST
Opposition groups in Syria have accused the country's security forces of killing hundreds of people in chemical weapons attacks.
The Syrian government has denied any involvement, but disturbing pictures have been posted online showing casualties, including children.
A weapons inspection team from the UN is already in Syria to check out claims of earlier alleged attacks.
Frank Gardner reports.