Russia's Defence Ministry said its air force had carried out strikes on Syrian rebels in support of the country's army, Russian news agencies reported on Saturday, amid an advance by forces opposed to Syrian President Bashar al-Assad.

Syria’s rebels seized most of Aleppo on Saturday as their sweeping advance ousted Russian forces from at least three military bases around the city.

Assad, has condemned the unexpected advance of anti-government Islamist rebels on the city of Aleppo as an attack on Syria's sovereignty. "Of course this is an encroachment on Syria's sovereignty in this region,