The Syrian army and allied militias are on the brink of breaking a three-year-long siege imposed on the city of Deir Ezzor by Isis militants, both war monitors and Syrian state media have said.

Media outlets and reporters sympathetic to the regime claimed on Monday that the siege had already been broken on the east side of the city, although activist-run Deir Ezzor 24 and the Syrian Observatory for Human Rights (SOHR) and other monitors have not yet confirmed the development.

Videos widely circulated on social media and shown by Lebanese Hezbollah-friendly TV channel al Manar supposedly showed Deir Ezzor residents preemptively celebrating Isis’ downfall.

Footage shows Isis schoolgirl Linda Wenzel being captured in Iraq

One reporter said that the Syrian flag had been raised above the entrance to the city’s Christian cemetery, although no picture was provided.

“The morale is very high,” Deir Ezzor governor Mohammed Ibrahim al-Samra told state TV.

The day before, the Syrian army had said it was between 24-48 hours from reaching the besieged zone after steadily advancing on the jihadist militants’ desert positions for several months with help from Lebanon’s Hezbollah and Russian air support.

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SOHR said on Monday that the advancing forces are less than 10 kilometres (six miles) from a besieged, government-occupied air base known as Brigade 137.

Syrian state TV and opposition-run Deir Ezzor 24 both said Assad’s forces and allied troops were much closer - in some cases only three kilometres (two miles) away from Isis’ front line.

Reaching the base will mean breaking the years-long siege which has left Deir Ezzor’s 70,000 residents reliant on UN air drops of food, medicine and other supplies - and at the mercy of the jihadists’ tyrannical interpretation of Islam.

In Raqqa - Isis’ other remaining stronghold in Syria - US-backed Arab and Kurdish fighters have also made steady gains on the militants, over the weekend pushing fighters out of their de facto capital’s historic Old City.

Thousands of civilians have fled the fighting in both areas - and hundreds have been killed by sniper fire and mines or caught up in US coalition and Russian bombing.

Liberated from Isis, women burn their burqas and men shave off their beards

Isis has lost swathes of territory across its so-called caliphate in both Syria and Iraq since the height of its powers in 2015.

Mosul, its de facto Iraqi capital and the largest city under the jihadists’ control, fell to Iraqi coalition forces in July after a gruelling nine-month-long battle.