Syrian opposition groups denounced a U.N.-sponsored international agreement to set up a transitional government in Syria, calling it ambiguous and a farce, even as U.S. Secretary of State Hillary Clinton acknowledged that there was no guarantee that the new deal would succeed in ending the 16-month-long Syrian crisis.

The agreement, signed on a day following the killing of dozens of civilians, including at least 30 in Friday's explosion in a suburb of Damascus, drew disapproval from the Syrian opposition with the Local Coordination Committees, or LLC, who said, The new agreement provides vague language which is open to interpretation.

This provides yet another opportunity for the regime's thugs to play their favorite game in utilizing time in order to stop the popular Syrian Revolution and extinguish it with violence and massacres across Syria, LLC said in a statement Sunday, as reported by CNN.

Syrians will not accept engaging in any political track while the killing continues, said Paris-based Syrian National Council spokeswoman Bassma Kodmani, as reported by United Press International.

The deal calling for a transitional government based on mutual consent gives veto powers to Syrian President Bashar al-Assad, the opposition and other groups. It also doesn't say how to implement the plans or how long it will take before the new government starts functioning.

We cannot say that there is any positive outcome today, Kodmani said Sunday. If we don't have firmness and clarity, we have more victims.

There is no guarantee that we are going to be successful, said Clinton. I just hate to say that.

However, in an interview Saturday in Geneva after the deal was announced, Clinton said Assad and his inner circle would be excluded from the proposed transitional government.

She added that there was no way anyone in the opposition would ever consent to Assad or his inside regime cronies with blood on their hands being on any transitional governing body.

The new agreement comes as a powerful blow to the Syrian regime, as its steadfast supporter Russia agreed for the first time to the transitional government replacing the regime.

[The Russians] have committed to trying, Clinton said. But they also admitted that they may or may not have enough leverage to convince not just one man but a family and a regime that their time is over.

Clinton floated the idea of the U.N. Security Council endorsing the plan, which would allow possible sanctions against Syria, if the agreement is not implemented.

People with blood on their hands are hopefully not the only Syrians, said the U.N.'s Syria envoy Kofi Annan, when asked if members of the Syrian regime would be part of the transitional government.

I think the government will have to be formed through discussion, negotiations and by mutual consent, Annan said after the U.N. meeting Saturday. And I will doubt that the Syrians, who have fought so hard for their independence to be able to say how they're governed and who governs them, will select people with blood on their hands to lead them.