Russia and China joined the rest of the U.N. Security Council on Saturday to authorize the deployment of up to 30 unarmed observers to Syria to monitor the country's fragile ceasefire as called for by U.N.-Arab League mediator Kofi Annan.

It is the first resolution the 15-nation council approved since the anti-government uprising in Syria began 13 months ago. Moscow and Beijing twice vetoed council resolutions condemning Syrian President Bashar al-Assad's assault on protesters opposed to his rule that has killed thousands of civilians.

Despite Saturday's unanimous vote, there were no signs that the divisions on the Security Council that have prevented it from taking action on the crisis have been overcome.

Syria's close ally and arms supplier Moscow was satisfied with the final draft of the resolution, though Russian U.N. Ambassador Vitaly Churkin made clear that there were limits to the kind of U.N. action Moscow could support.

Out of respect for the sovereignty of Syria we have cautioned against destructive attempts at external interference or imposing any kind of illusory fixes, he said.

Russia has accused the United States and Europe of tricking it into using a U.N. mandate to protect civilians in Libya to enable NATO to engage in regime change. Russia abstained from a March 2011 vote and allowed a council resolution authorizing all necessary measures to protect Libyan civilians to pass.

French Ambassador Gerard Araud added that the newfound unity on the council may not be permanent. Our consensus is fragile, he said.

Before agreeing to support what was originally a U.S.-drafted text, Russia had demanded the U.S. and European delegations dilute it so that it would not demand that Syria comply with the resolution. The approved resolution uses softer language so that it calls upon Syria to implement it.

Churkin also demanded that the council urge the opposition as well as the Syrian government to change its behaviour.

The approved resolution has the council condemning the widespread violations of human rights by the Syrian authorities, as well as any human rights abuses by armed groups, recalling that those responsible shall be held accountable.

It calls on all parties, including the opposition, immediately to cease all armed violence in all its forms.

The text also includes a vague warning to Damascus, saying the council would assess the implementation of this resolution and to consider further steps as appropriate.

'50 VIOLATIONS'

Syrian Ambassador Bashar Ja'afari reiterated Damascus' commitment to Annan's six-point peace plan, which calls for an end to fighting, withdrawal of troops, dialogue between the government and opposition and a political transition for the country.

The time for violence is gone, he said, though he accused the opposition of 50 violations of the truce since Thursday.

Western council members welcomed the adoption of the resolution but had harsh words for Assad's government.

U.S. Ambassador Susan Rice condemned what she said was Damascus' murderous rampage over the last year, adding that the sporadic violence that has broken out since Thursday's ceasefire casts doubt on the government's commitment to peace.

Asked if the Syrian forces' shelling on Saturday of the battered city of Homs was a violation of the ceasefire, Rice said absolutely.

British Ambassador Mark Lyall Grant said Syrians had suffered unimaginable brutality at the government's hands.

Lyall Grant and French Ambassador Araud both said that Assad's forces have killed over 10,000 people, higher than the U.N. estimate of 9,000. Syrian authorities, who blame foreign-backed militants for the violence, say 2,500 soldiers and police have been killed.

The responsible perpetrators of this barbaric repression of a peaceful group of (demonstrators) will not go unpunished, Araud said. Today finally the Security Council is with a single voice recognizing the criminal responsibility for these acts.

Annan had asked the council to approve the deployment of an advance team of monitors as soon as possible. U.N. Secretary-General Ban Ki-moon and Annan said in a joint statement that they would work to deploy the team as quickly as possible.

Annan is planning for an observer force that will have up to 250 monitors, though its full deployment will require a new Security Council resolution.

I think we do have a good basis in the resolution for the advance team, a good basis to work on the further mandate, Churkin said. I hope we learn from our experience of the past few days and so it shouldn't take too long.

He also complained about the failure of the U.N. secretariat to reach agreement with the Syrian government on the parameters of the mission and suggested it was the U.N.'s fault, above all Norway's General Robert Mood, who led a U.N. negotiating team in Syria. Damascus' consent is needed for the team's deployment.

Churkin accused Mood of abruptly leaving Syria, sort of fleeing his position in the middle of action.

U.N. diplomats say that it is becoming increasingly awkward for senior U.N. officials to engage with a Syrian government that has failed to keep promises to halt the violence and which the Office of the High Commissioner for Human Rights has said may be guilty of grave human rights violations and war crimes.

(Reporting By Louis Charbonneau and Michelle Nichols; Editing by Vicki Allen and Philip Barbara)