Syrian and Russian jets are stepping up strikes on opposition forces in northern Syria in retaliation for the sudden offensive that has cost the autocratic regime control of the country’s second largest city,

Syria's civil war has taken a dramatic turn, with dictator Bashar Assad once again leaning on Russian support after a shock offensive by Islamist rebels in Aleppo.

As things stand this morning, the Syrian army says that anti-government forces have now taken control of "large parts" of Aleppo. Meanwhile, the country's president is vowing to "defend [Syria's] stability and territorial integrity in the face of all terrorists and their backers".

The advance on Aleppo followed a shock offensive launched on Wednesday, as fighters swept through villages and towns.

The insurgent offensive, shocking for its speed, has posed the most serious challenge to President Bashar al-Assad in years.

Thousands of Syrian insurgents took over most of Aleppo on Saturday, establishing positions in the country's largest city and controlling its airport before expanding their shock offensive to a nearby province.

Syria and Russia are stepping up their retaliatory strikes on forces in northern Syria after they lost control of the country’s second-largest city.

Syrian rebels drove military vehicles around Aleppo province as clashes with Syrian government forces escalated. Fighting in northwestern Syria over the past three days has claimed the lives of 27 civilians,