Syrian rebels have launched their first major offensive in the country in four years, claiming to have beaten government forces back several miles and captured a dozen villages west of Aleppo.

The surprise assault occurred around Aleppo, a government-held city and one of the focal points of fighting in Syria’s civil war.

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).