The north-west is dominated by the Islamist militant group Hayat Tahrir al-Sham (HTS), but Turkish-backed rebel factions - known as the Syrian National Army (SNA) - also control territory there with the support of Turkish troops.

Opposition forces seeking to overthrow Syria's President Bashar al-Assad launched their biggest offensive in years last week, retaking the northern city of Aleppo and driving government forces out of the region.

A surprise offensive by rebel forces opposed to Syrian President Bashar al-Assad's regime has led to a new round of fighting in a largely static civil war.