Putin demands evidence of Syrian chemical attack from US

Russia's President Vladimir Putin is demanding America show what evidence it has that the Syrian government is to blame for an alleged chemical weapons attack.

President Barack Obama said he is considering limited military action after its intelligence reports that more than 1,400 people were killed in Damascus last week.

The United Nations team charged with finding independent evidence of the gas attack in Damascus has now left the country.

The UN said it could take two weeks before its inspectors are able to report their findings.

Meanwhile, a rally is being held in London in protest at the potential for military intervention by the US in Syria.