Intense airstrikes overnight drove Syrian rebels back from the edge of Hama, a major city whose fall would pile pressure on President Bashar al-Assad, both sides said on Wednesday.

The rebel coalition consists of "well-established armed Islamist factions who, despite their differences, are united in fighting Assad and Iran-backed militias", said CNN. But the driving force behind the fighting is Hayat Tahrir al-Sham (HTS), a "formidable" and controversial faction with deep roots in Syria's ongoing civil war.