Iranian-backed militias entered Syria overnight from Iraq to bolster Bashar al-Assad’s retreating army, after rebels took strongholds across northern Syria. 

Iran sent thousands of Shi’ite militias during the Syrian civil war in 2011 which, alongside Russia’s air power, enabled Syrian President Assad to cling on to power and regain most of his territory.

“These are fresh reinforcements being sent to aid our comrades on the front lines in the north,” a senior Syrian army source said, adding the militias included Iraq’s Katiab Hezbollah, Fatemiyoun and Hashd al Shaabi fighters.

Moscow’s air force has come to Assad’s aid once more, after rebels drove the Syrian army out of Aleppo and Idlib on Sunday.

The conflict also appeared to be widening, with Turkish-backed forces reportedly attacking the PKK/YPG terror group.