Tens of thousands of Syrians shouting "We want freedom!" carried slain protesters through the streets Saturday, one day after security forces killed at least 28 people during the largest anti-government demonstrations since the uprising began.

The funerals came as prominent opposition figures held a conference in neighboring Turkey seeking ways to oust Syrian President Bashar Assad, with a prominent dissident saying he leads "the most tyrannical regime in the world."

"The regime had kidnapped the entire state, and we want it back," said Haitham al-Maleh, who headed the conference in neighboring Turkey. The 80-year-old lawyer, who spent years in Syrian prisons for his political activism, recently left Syria out of fear for his life.

Activists say the government's crackdown on dissent 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.

On Friday, hundreds of thousand of Syrians took to the streets across the country in the largest show of the uprising's strength.

Syrians poured into areas where the government crackdown has been most intense -- a sign that security forces cannot break the revolt. They also turned out in their thousands in the capital, Damascus, which until now had seen only scattered protests.

A witness in Damascus told The Associated Press on Saturday that tens of thousands from Damascus and the suburbs held funerals for slain protesters, carrying the bodies overhead on stretchers and shouting "God is Great!" and "We want freedom!"

Like most witnesses in Syria, he spoke on condition of anonymity for fear of retribution. The government has banned most foreign media and restricted local coverage, making it difficult to independently confirm accounts on the ground.

The Local Coordinating Committees, which help organize and track the protests, said they have the names of 28 people confirmed dead. Other estimates of the death toll were as high as 41.

Also Saturday, security forces continued a weekslong operation in the restive Idlib province, near the Turkish border. The London-based Syrian Observatory for Human Rights said security forces raided homes in the village Kfar Nabl and made scores of arrests.

The government crackdown has led to international condemnation and sanctions.

"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," U.S. Secretary of State Hillary Clinton told reporters in Turkey on Saturday. "The brutality has to stop, there must be a legitimate sincere effort with the opposition to try to make changes."

Saturday's opposition conference in Turkey -- called the National Salvation Conference -- was attended by some 400 dissidents looking to form a unified opposition to Assad, whose family has ruled Syria for more than 40 years.

The conference is part of a series of meetings the opposition has held recently in Turkey and Europe in an attempt to organize their ranks. Activists in Damascus also took part in Saturday's meeting by telephone.

Organizers had planned to hold a conference in Damascus in tandem with the Turkey meeting, but it was canceled after Friday's bloodshed. The Local Coordination Committees, which help organize the protests, said at least 14 people were killed near a hall where the conference was to be held.

In Turkey, al-Maleh accused Assad of leading a "fascist regime" and praised the "heroic people of Syria" for rising up against him.

Opposition figure Mashaal Tammo, addressing the conference by phone from Damascus, said Assad had lost his legitimacy to rule and called on him to step down.

In an emotional speech, he said the "the existence of the regime was no longer justified," and called for a peaceful transition to a civil, pluralistic and democratic state.