Russia and China's veto Saturday of a U.N. resolution on the bloodshed in Syria is a "shockingly callous betrayal" of the Syrian people, Amnesty International said.

Moscow and Beijing have acted in a "completely irresponsible" way, the London-based human rights group added.

A member of the opposition Syrian National Council said the group took control of Syria's embassy in the Libyan capital on Saturday without meeting any resistance.

"The Syrian National Council has taken physical control of the embassy today," said council member Anas al-Khalid.

Information Minister Adnan Mahmoud on Saturday accused Syrian rebels of shelling the protest hub of Homs to swing a U.N. Security Council vote in their favor.

"The reports on some satellite channels that the Syrian army shelled neighborhoods in Homs are fabricated and unfounded," Mahmoud said in a statement to Agence France Presse.

The government is trying to negotiate the withdrawal of al-Qaida linked militants from Zinjibar, capital of Abyan province in southern Yemen, tribal and government officials said on Saturday.

The negotiations, taking place through tribal mediators, are "ongoing," a government official told Agence France Presse on condition of anonymity, without giving further details.

Russia and China on Saturday vetoed a U.N. Security Council resolution condemning the Syrian government's murderous crackdown on protests for the second time.

Western governments reacted with fury to the new block on U.N. action over President Bashar Assad's 10 month-old assault on demonstrators which followed weeks of acrimonious negotiations over the text.

President Barack Obama on Saturday accused Syrian President Bashar Assad's government of murdering civilians in an "unspeakable assault" in the city of Homs, and demanded that Assad step down.

"Assad must halt his campaign of killing and crimes against his own people now. He must step aside and allow a democratic transition to proceed immediately," Obama said in a statement.

Palestinian president Mahmoud Abbas and Hamas chief Khaled Meshaal will meet on Sunday in Qatar, Fatah party spokesman Azzam al-Ahmed told Agence France Presse on Friday.

Abbas and Meshaal "will discuss forming a government and political questions after the failure of talks" with Israel, Ahmed said.

U.S. Secretary of State Hillary Clinton told her Russian counterpart Sergei Lavrov that Washington will push for a U.N. Security Council vote on Syria later Saturday, a U.S. official said.

However, it was not clear what if any progress Clinton had made in bridging differences with Foreign Minister Lavrov over the terms of an amended Arab- and Western-backed draft resolution in New York.

The Arab League's parliaments chief called on member states to expel pro-regime Syrian ambassadors, saying that President Bashar Assad's government is continuing to kill Syrian protesters.

Ali Salem al-Diqbassi, the 88-member advisory body's speaker, said that Arab League countries should carry out a decision to cut diplomatic and economic ties with Syria as Assad faces down pro-democracy protests with violence.

Iranian naval ships docked on Saturday in the Saudi port city of Jeddah on a mission to project the Islamic republic's "power on the open seas," the Fars news agency reported.

The supply ship Kharg and Shaid Qandi, a destroyer, docked in the Red Sea port in line with orders from Iran's supreme leader Ayatollah Ali Khamenei, it quoted navy commander Admiral Habibollah Sayari as saying.