In Washington, a call for air strikes against President Bashar al Assad's regime.

U.S. Senator John McCain says the time has come for a new U.S. policy regarding Syria.

SOUNDBITE: U.S. Senator John McCain saying:

"Rather than closing off the prospects for some kind of negotiated transition that is acceptable to the Syrian opposition, foreign military intervention is now the necessary factor to reinforce this option. Assad needs to know that he will not win."

The former presidential candidate stressed the need for urgent action to prevent more civilian deaths.

SOUNDBITE: U.S. Senator John McCain saying:

"Providing military assistance to the Free Syrian Army and other opposition groups is necessary, but at this late hour, that alone, will not be sufficient to stop the slaughter and save innocent lives. The only realistic way to do so is with foreign air power."

New amateur video posted to the internet purports to show government forces firing on the central city of Homs.

Reuters cannot confirm the content of this video, but its release comes amid a military crackdown on rebels throughout the country. Activists say Assad's forces have destroyed a key opposition outpost during the government's 26-day siege on the city.

Deborah Gembara, Reuters.