Rebels say the campaign responded to stepped-up strikes in recent weeks against civilians by the Russian and Syrian air forces on areas in southern Idlib province, in Syria's far northwest, and to pre-empt any attacks by the Syrian army, which they said was building up troops near front lines with rebels.

A radical Islamist group unleashed its biggest military incursion against Syrian regime forces since 2020 in the northwest of the war-ravaged Syrian Arab Republic, triggering Russian and Syrian warplanes on Thursday to bomb the insurgent offensive.