The United States closed its embassy in Syria and pulled out all its staff on Monday amid growing security concerns as President Bashar al-Assad's government intensifies its bloody crackdown.

Britain also recalled its envoy, but U.S. President Barack Obama stressed the importance of diplomacy and said it was a very different situation from Libya, where Western military intervention helped oust Moammar Gadhafi.

The opposition Syrian National Council on Monday urged Syrians around the world to hold protests outside their embassies, accusing the regime of "genocide" in Homs.

"We call on everyone to surround Syrian embassies and stage sit-ins outside them," the SNC said in a statement received by Agence France Presse.

Saudi Arabia on Monday called for "critical measures" to be taken on Syria, warning of an impending "humanitarian disaster" after the U.N. Security Council failed to pass a resolution on the crisis there.

"The U.N. Security Council's failure to pass a resolution in support of the Arab Initiative must not prevent the taking of critical measures to protect innocent lives and stop the bloodshed and all acts of violence that threaten serious consequences for the Syrian people and regional stability," a cabinet statement said.

Turkish President Abdullah Gul on Monday expressed his country's disappointment over the veto by China and Russia of a U.N. resolution on the Syrian crisis, saying that the cold war era was over.

"I'd like to say that we are upset about the vote at the United Nations," Gul told a televised news conference with his South Korean counterpart, Lee Myung-Bak.

France and Germany will not accept the "blocking" of international action on Syria, French President Nicolas Sarkozy said Monday, after Russia and China vetoed a U.N. resolution on the crisis.

After a meeting with German Chancellor Angela Merkel, Sarkozy also said he would call Russian President Dmitry Medvedev on behalf of France and Germany later Monday to discuss the international community's response to the crisis.

Syrian army defectors on Monday announced the creation of a higher military council to "liberate" the country from President Bashar al-Assad.

"After consultations with dissident officers, an accord was reached to form the Higher Revolutionary Council in order to liberate Syria from this gang," the council said in a statement, referring to Assad's embattled regime.

Syria's Muslim Brotherhood on Monday accused Russia, China and Iran of being complicit in what it said was a "massacre" being carried out by the embattled regime in Damascus, which it likened to the Nazis.

"We consider Russia, China and Iran as direct accomplices to the horrible massacre being carried out against our people," the group's spokesman Zouheir Salem said in a statement issued from London.

A "terrorist group" blew up an oil pipeline on Monday in the Syrian protest hub of Homs, the official SANA news agency reported.

"An armed terrorist group launched a sabotage attack on an oil transport pipeline in the al-Sultanieh area near Jober in the Baba Amro neighborhood of Homs, triggering a fire," the agency said.

Syrian authorities on Monday said armed "terrorist gangs" were behind the latest violence in Homs, where activists accused government forces of launching a fierce assault on the flashpoint city.

State television said the alleged gangs had been planting bombs which exploded while they were being primed, killing many of the "terrorists."

Protesters and police clashed again overnight outside Cairo's security headquarters in the wake of deadly football violence and amid calls by activists for civil disobedience in Egypt.

Police fired birdshot at demonstrators in roads leading to the interior ministry, the scene of days of clashes sparked by the deaths of 74 people on Wednesday in football-related violence in the northern city of Port Said.