Fighter jets circle the air - as the Syrian government reportedly launches air strikes across Syria on Thursday.

Amateur video that could not be independently verified by Reuters purportedly showed the aftermath - outside of Damascus and in the town of Douma - after forces loyal to Syrian President Bashar al-Assad bombed the areas.

Opposition forces said warplanes also struck a residence in the northern town of Hayyen - killing at least eight civilians.

Rebels hold a tenuous grip on the north - and also control a group of suburbs near Damascus - that recently have been pounded by government forces controlling the capital city center.

The civil war in Syria has become the longest and by-far the deadliest of the conflicts stemming from the 2011 Arab spring.

After 21 months, the United Nations says the death toll now stands at more than 60,000 people.