The rebel group, the Free Syrian Army, has said it rejects the Russian initiative to put the Syrian government's stock of chemical weapons under international control.

The group, the main, Western-backed rebel fighting force, made the statement in a video posted on the internet.

In it, the FSA's military commander, General Salim Idris, said: "The international community should not be content with withdrawing chemical weapons which are a criminal instrument but to hold the perpetrator accountable and prosecute him at the International Criminal Court.

"Removing the criminal tools is one matter and holding the criminal accountable is another."