Syria's Bashar al-Assad was branded a coward on Tuesday by his onetime friend and ally, Turkish Prime Minister Recep Tayyip Erdogan, who urged him to quit or face a bloody death like other dictators.
At the United Nations, a key committee condemned the Syrian government's deadly crackdown on protests, heightening international pressure on Assad.
Only 12 nations joined Syria in opposing the resolution backed by 122 countries at the General Assembly's human rights committee, with Syria's UN envoy accusing Britain, France and Germany of "inciting civil war" by pressing for the vote.
The resolution "strongly condemns the continued grave and systematic human rights violations by the Syrian authorities," highlighting the "arbitrary executions" and "persecution" of protesters and human rights defenders.
Assad is under mounting pressure to step down over his regime's eight-month crackdown on protests that the United Nations says has killed more than 3,500 people.
Security forces killed 17 people across the country on Tuesday, including six boys, the Britain-based Syrian Observatory for Human Rights said.
Among them were four boys aged 10, 11, 13 and 15 "indiscriminately" gunned down in the Hula area in the flashpoint central province of Homs, the watchdog said in a statement, while a fifth, aged six, died in Homs city.
A 12-year-old boy also died when security forces fired on Demonstrators in the eastern oil hub city of Deir Ezzor, it said.
In his fiercest criticism yet of his former personal friend, Erdogan called on Assad to "quit power before more blood is shed... for the peace of your people, your region and your country."
After weeks of mounting criticism of Assad, it was the first time the Turkish premier had directly called for his removal, becoming the second leader of a neighbouring country to do so after Jordan's King Abdullah II.
"Bashar al-Assad is saying he will fight to the death. Fighting your own people... is not heroism but cowardice," Erdogan told parliament, referring to a recent interview with Assad published by the Sunday Times in London.
"If you want to see someone who fought and died, take at look at Nazi Germany, take a look at Hitler, take a look at Mussolini and Romania's Ceausescu," he said.
Adolf Hitler died in his bunker as Allied forces closed in on Berlin, wartime Italian leader Benito Mussolini was strung up from a lamp post by an angry mob, and Romanian communist dictator Nicolae Ceausescu was executed by firing squad on Christmas Day 1989.
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If Assad had failed to learn lessons from history, Erdogan invited him to consider the more recent fate of Libya's long-time strongman Moamer Kadhafi who was killed by his opponents after being chased from power.
Erdogan also asked Assad why he failed to display the same fighting spirit to win back the Golan Heights, a rocky plateau which Israel captured from Syria during the 1967 Middle East war and unilaterally annexed in 1981.
"You are talking about fighting to the death. Why didn't you fight to the death for the Golan Heights occupied by Israel?" Erdogan asked.
He insisted Turkey had no intention of interfering in Syria's domestic affairs but added "we cannot remain indifferent" to what happens in a neighbouring country with which Turkey shares a 910-kilometre (570-mile) border.
Turkey has become increasingly vocal in its criticism of Assad after its diplomatic missions came under attack by pro-government demonstrators in several Syrian cities earlier this month.
Tensions deteriorated further on Monday when two busloads of Turkish pilgrims who were in Syria on their way back from the hajj in Mecca were attacked by gunmen.
The Syrian National Council (SNC), the largest and most representative opposition grouping, said it was in talks with activists and dissidents to prepare for the transition "in accordance with the Arab League initiative."
On Monday, British Foreign Secretary William Hague urged Syria's opposition to unify to become stronger as he held his first meetings with their representatives in London.
French Foreign Minister Alain Juppe issued a similar call last week, saying "the SNC must get organised" before it can win recognition from the French government.
The SNC has so far been officially recognised only by the post-Kadhafi Libyan authorities.
Juppe said on Tuesday there were no plans for Libyan-style military intervention in Syria.
He said that was partly "because the SNC prefers to continue with peaceful efforts," but also because "Arab countries have not asked for (it) and because of the difficulty in obtaining a resolution from the UN Security Council as a result of Russia's veto" right.