Dubai Russia’s unrelenting support for the Bashar Al Assad regime is helping to slide Syria into civil war, US Secretary of State Hillary Clinton said Friday.

“We believe that the continuous supply of arms has strengthened the Al Assad regime,” she said.

Russian President Vladimir Putin Friday denied the claim, saying Moscow supported neither side.

“I reject that. I think they are, in effect, propping up the regime at a time when we should be working on a political transition,” Clinton said.

Despite the friction between the US and Russia over Syria, analysts mainly agree that the US cannot effectively solve the problem without Russia.

Meanwhile, new reports of civilian killings by pro-government gunmen emerged. A video was posted on YouTube allegedly showing 13 men summarily executed after their bus was stopped by the Shabiha gunmen in the western town of Al Qusayr.

Last week over 100 civilians were killed in Al Houla, prompting worldwide outrage. As Syrians poured into streets yesterday to commemorate the victims, one poster read, “to the civil world: the death of the last free Syrian comes very close.” In Geneva, the UN Human Rights Council condemned Syria over the Al Houla massacre.