Hundreds of Syrian dissidents debated strategies to oust Bashar al-Assad’s regime yesterday in Istanbul as US Secretary of State Hillary Clinton called for a halt to the “brutal” repression of protests.

A simultaneous gathering scheduled to take place in Damascus was cancelled after at least 28 civilians were killed, including 16 in the capital, in demonstrations on Friday, activists said.

They said security forces arrested almost 300 people in a clampdown on the largest anti-regime rallies in four months that saw more than a million people take to the streets in the cities of Hama and Deir Ezzor.

Clinton told CNN Turk television on a two-day visit to Syria’s northern neighbour: “The brutality has to stop. There must be a legitimate, sincere effort with the opposition to try to make changes.

“I don’t know whether that will happen or not,” she added.

Some 350 dissidents attended Syria’s opposition meeting in Istanbul, which was held in a packed conference hall decorated with Syrian flags and began only after a minute of prayer for the victims.

“The Congress is expected to endorse a roadmap aiming to take the country from the state of totalitarianism and tyranny towards democracy...,” organisers of the so-called National Salvation Congress said in a statement.

Participants came from various countries and belonged to many different opposition groups, according to coordinators.

“We have a paper with our view for the future, for changes in Syria, for democracy and freedom,” Haitham al-Maleh, a senior opposition activist told AFP.

“We will see if anyone has any (objections) to our paper, we will make corrections possibly and then we will elect a group of maybe 15 people to continue working outside Syria. We will connect those inside and outside Syria,” said the human rights campaigner.

Opposition groups have held two other meetings in Turkey since anti-regime demonstrations began in March.