The fighting is a significant escalation since rebels launched a surprise offensive earlier this week, seizing towns and villages as they cut a path toward Syria’s second-largest city.

Fierce fighting has been taking place on Friday in Aleppo’s western neighbourhood, where the national army has lost the centre of the key district of New Aleppo that the Hezbollah and the Iranian militias have left abandoned.

Following fighting carried on through night, opposition forces advanced on outskirts of the city, seizing control of 70 settlements and strategic locations - Anadolu Ajansı

Syrian rebels have launched a large-scale attack on regime forces in western Aleppo, according to a Free Syrian Army source and local residents, marking the first major flare-up in years between both sides.

By the end of the first day of the offensive, the rebels had advanced into the western Aleppo countryside, taking them within 10km (6 miles) from the outskirts of Aleppo city, according to the UK-based Syrian Observatory for Human Rights (SOHR).

Thousands of Syrian insurgents have pushed on with their advances on government-held areas in the country’s northwest

Scores of people were killed after forces opposed to the government of President Bashar al-Assad overtook a Syrian military base, a monitoring group reported.

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

Syrian armed rebels have entered Aleppo just three days into their surprise offensive, marking the first time they have set foot in the country’s second largest city since government forces recaptured the city in 2016.