Damascus (Creative Commons)

The groups spoke under the National Coordination Body for Democratic Change in Syria. The groups sided with the armed rebels fighting Assad's rule, reports The Daily Beast.

The groups have urged for a peaceful settlement to the civil war that has killed tens of thousands in 18 months. While the groups have sided with the rebels, they are urging for a ceasefire.

The meeting was held in Damascus by groups that are usually divided. Opposition is divided between the majority in exile and those in Syria.

Assad usually restricts criticism, but the conference was allowed to be held without restrictions, opposition leaders told the BBC.

Reach Senior News Editor Hannah Madans here.