The Syrian National Council, a coalition of groups opposed to President Bashar al-Assad, is holding its first congress in Tunisia.
About 200 members of the SNC are meeting near the capital Tunis in a bid to further unify the Syrian opposition.
Correspondents say delegates hope the council will emerge looking more like a government-in-waiting.
Earlier, thousands of anti-government protesters again took to the streets across Syria following Friday prayers.
Activists said at least six people had been killed by security forces in the central city of Homs, which has become a focal point for unrest.