PRESS ASSOCIATION -- Tens of thousands of Syrians shouting "We want freedom!" have carried killed protesters through the streets as opposition figures meeting in Turkey called for a united front to bring down the 40-year ruling dynasty of the Assad family.
Syrian security forces killed at least 28 people during the largest protests since the uprising began more than four months ago, activists said.
Hundreds of thousands of people poured into the streets nationwide, but they were met with gunfire and tear gas.
"The regime has kidnapped the entire state, and we want it back," said Haitham al-Maleh, one of Syria's most prominent dissidents, who led today's opposition conference in Istanbul. The 80-year-old lawyer spent years in Syrian prisons for his political activism.
Syria's crackdown on the protests has led to condemnation and sanctions.
US Secretary of State Hillary Clinton said that President Bashar Assad had dashed hopes of reform.
"What's happening in Syria is very uncertain and troubling because many of us had hoped that President Assad would make the reforms that were necessary," she said in Istanbul. "The brutality has to stop, there must be a legitimate, sincere effort with the opposition to try to make changes."
"(On Friday) we witnessed the largest demonstrations to date in Syria, an effort to try to convey directly to the government the pent-up desire of the Syrian people for the kind of reforms that they have been promised," she added.
Activists say the government's crackdown has killed some 1,600 people since March, most of them unarmed protesters. But the regime disputes the toll and blames a foreign conspiracy for the unrest, saying religious extremists - not true reform-seekers - are behind it.
The conference was an attempt to form a unified movement that can offer a realistic alternative to Assad, whose supporters argue that he is the only force who can guarantee stability in a region beset by civil wars and religious strife.
Although Assad's regime is shaken, he still draws from a significant well of support from the middle classes, business community and religious minorities.