Amateur footage uploaded to social media websites appears to show rebel fighters brazenly driving round the Al-Midan district of Damascus in pick-up trucks mounted with heavy machine-guns.
Other videos also placed on the internet by Syrian activists seems to show the aftermath of rebel attacks on government security posts in the Hajar Al-Aswad area of the Syrian capital.
The Telegraph is unable to verify the date or location of this footage as independent media are severely restricted inside Syria.
In Washington, the White House spokesman Jay Carney warns countries that support the Assad regime that they will "end up on the wrong side of history".
