Syrian jihadists launched their first major offensive in four years against government positions near Aleppo, claiming to have captured several villages on the edge of the city.

The surprise offensive by rebel forces belonging to Hayat Tahrir al-Sham (HTS) and allies saw heavy fighting on the western side of the city where front lines had become largely frozen.

At least 57 people were killed in the clashes, a group monitoring the war said.

The Syrian Observatory for Human Rights said “26 members of Hayat Tahrir al-Sham and allied factions” were killed, as well as “31 members of the regime forces”.

There were also unconfirmed reports that the jihadists had captured the base of the Syrian army’s 46th Regiment base, only three miles from Aleppo.

The air forces of both Syria and its ally Russia struck the attacking jihadists in the area for the first time in years, the UK-based Observatory said.