Annan on Syria: 'We are at a tipping point'
29 May 2012 Last updated at 17:41 BST
A number of Western countries are expelling Syrian ambassadors and officials in the strongest show so far of international outrage over the massacre of more than 100 people, including many children in the town of Houla.
The United States, Britain, France, Germany, Spain, Italy, the Netherlands, Australia and Canada are all taking part in the co-ordinated action.
In Damascus the UN special envoy, Kofi Annan, told President Assad that his peace plan required bold steps to halt the violence.