The White House on Tuesday condemned the Syrian regime's unrelenting violence against protesters, saying it was "past time" for the U.N. Security Council to take actions against Damascus.

White House spokesman Jay Carney said Syria had failed to comply with standards set by Arab observers monitoring the situation, adding that "as sniper fire, torture, and murder in Syria continue, it is clear that the requirements of the Arab League protocol have not been met."

An Arab League observer mission currently in strife-ridden Syria "remains useful" even if it cannot impose an Arab peace plan in the country, the leader of the main opposition group said Tuesday.

"We believe that this mission remains useful even if it does not lead to the implementation of the Arab plan," Syrian National Council (SNC) leader Burhan Ghalioun said after talks with Portugal's foreign minister.

Arab foreign ministers working on the Syrian crisis will meet in Cairo on Saturday to discuss the first report by an observer mission in Damascus, the Arab League said on Tuesday, as fresh violence killed 10 civilians and 18 regime troops, according to activists and a rights watchdog.

"The Arab League committee on Syria will meet Saturday at the Arab League headquarters," Assistant Secretary General Ahmed Ben Hilli told reporters.

A Syrian media rights group on Tuesday demanded a full inquiry into the death of a journalist who was reportedly shot in the head by gunmen waiting for him outside his Damascus home.

Shukri Ahmed Ratib Abu Burghul died on Monday in a Damascus hospital from gunshot wounds suffered on December 30, Reporters Without Borders (RSF) said.

Syria's ruling Baath party said Tuesday that it will hold its 11th party congress next month as it faces an unprecedented popular uprising demanding its leadership resign.

"The regional command of the Baath Arab Socialist Party has decided to hold its 11th regional congress during the first week of February," the official Al-Baath newspaper reported.

Armed clashes erupted in the center of the Libyan capital Tripoli on Tuesday, killing two, as gunmen traded anti-aircraft and heavy machinegun fire, witnesses said.

Meanwhile, Al-Arabiya television reported that six people were killed in the fighting.

Egyptian prosecutors on Tuesday portrayed ousted president Hosni Mubarak as a "tyrannical leader", as they made their opening arguments in his murder trial.

The ailing 83-year-old former strongman, who was wheeled into court on a stretcher, is accused of involvement in the deaths of protesters during the uprising that overthrew him in February.

French President Nicolas Sarkozy demanded Tuesday that Syrian strongman Bashar Assad step down, accusing him of overseeing sickening "massacres" against his own people.

Sarkozy told an audience of French military personnel that the Syrian people should be allowed "to freely choose their own destiny" after facing what he denounced as brutal persecution that inspires "disgust and revulsion.”

Saboteurs attacked a gas pipeline near the flashpoint Syrian city of Homs on Tuesday, the official SANA news agency reported.

"A terrorist group has targeted a gas pipeline near Rastan" in the central province of Homs, said SANA, referring to the bastion of protests against the regime of President Bashar Assad.

Egyptians were voting on Tuesday in the final round of a landmark post-revolution election that has propelled Islamist movements into the center stage of politics.

Around 15 million eligible voters have their chance to cast ballots for the first parliament since an uprising overthrew veteran president Hosni Mubarak last February.