The Syrian military has rushed in reinforcements to push back insurgents from advancing farther into the northern Hama countryside after they seized Aleppo in a surprise offensive

The Syrian government has been fighting back against opposition forces with airstrikes after they took over large swathes of land in a lighting advance which has caused embarrassment to President Bashar Al-Assad.

Thousands of Syrian insurgents fanned out inside Aleppo in vehicles with improvised armor and pickups, deploying to landmarks such as the old citadel on Saturday, a day after they entered Syria's largest city facing little resistance from government troops, according to residents and fighters.

Rebel forces opposing President Bashar al-Assad have launched their biggest offensive in years this week, controlling a majority of Syria's second city of Aleppo according to a monitor.

Jihadists and their Turkish-backed allies shelled Syria's second city Aleppo on Friday, in a major offensive against government troops that has sparked some of the deadliest fighting the country has seen in years.

The Syrian military said on Saturday that dozens of its troops had been killed during an insurgent attack in northwestern Syria and that rebels had managed to enter large parts of Aleppo city, forcing the army to redeploy.

At least 16 people were killed in an airstrike on central Aleppo on Saturday, a war monitor reported, amid renewed fighting in war-torn Syria. Some 20 others were reportedly injured in the strike on a roundabout,