A civilian rescue group in Syria posted dramatic footage of children being rescued from a bombed out building, believed to be in Douma, 15 kilometres northeast of the capital, Damascus.

The images show several children being pulled from rubble inside a building by the 'white helmets', a group of volunteer rescuers. As they carry the children outside, the sound of an incoming projectile is audible, followed by a large explosion.

It was not immediately clear who fired the projectile, but the Syrian military has targeted the area in the past in an effort to oust rebels fighting the government of Bashar al-Assad.

Syria's four-year civil war has killed an estimated quarter of a million people and driven 10 million from their homes.