The retaking of Aleppo marks the first major development in years in Syria's grinding civil war, which had largely fallen from the world's headlines. It also raises fresh questions about the opposing sides,

Airstrikes also hit residential buildings in the city of Idlib, which has become a refuge for people displaced by the civil war, killing at least 12 civilians, according to the White Helmets, an independent rescue organization.

Syrian opposition forces in recent days seized Aleppo, one of Syria's largest cities, reigniting a 13-year civil war.

A surprise offensive by rebel forces opposed to Syrian President Bashar al-Assad's regime has led to a new round of fighting in a largely static civil war.

The 13-year civil war in Syria has roared back into prominence as insurgents seized Aleppo in a shock offensive marking a major threat to president Bashar al-Assad’s brutal regime.The push – which saw insurgents seize the country’s second-largest city – is among the strongest in years,