Syrian diplomats are being expelled from several western countries after a recent massacre left more than 100 people dead, many of them children.
The killings in the Syrian town of Houla have caused international outrage. Britain, France and the US are among those now showing diplomats to the exit.
In Paris on Tuesday, activists turned out to vent their anger against the Syrian regime.
French president Francois Hollande is not ruling out military intervention.
“Military action is not excluded, on the condition that it is done in line with international law,” Hollande said.
“It’s up to me and others to convince the Russians and Chinese, but also to find a solution that is not necessarily military,” he continued.
International envoy Kofi Annan has been meeting with President Bashar al-Assad in Damascus.
He is trying to salvage a peace plan that many observers say is now in tatters.
After the talks, Annan described Syria as being at “tipping point.”
“Words are wonderful but action is better. What is important is to demonstrate through action a real commitment to the plan. This is what the international community is asking for now – action, not words,” Annan said.
The Syrian regime maintains it had nothing to do with the massacre in Houla.