SYRIAN troops in besieged Deir Ezzor were hard pressed to hold off the last-ditch Isis bid to capture the eastern city yesterday.

On Sunday the extremists broke through army lines on the southern side of the city after three days of fierce fighting, capturing Umm Abboud hill and several points in the Panorama area between the city and its isolated airport.

But Isis was unable to fortify its positions and was forced to withdraw under heavy Russian air attacks.

With its de-facto capital of Raqqa now surrounded on three sides by US-backed Kurdish-led Syrian Democratic Forces (SDF) militia, Isis is seemingly desperate to take Deir Ezzor in Syria’s oil-rich desert east. SDF spokeswoman Jihan Sheikh Ahmed said the assault on the city “will begin in a few days.”

In the country’s centre the army claimed it had taken more than 500 square miles of desert south-east of Palmyra from Isis in its offensive to lift the siege of Deir Ezzor.

In neighbouring Iraq, Shi’ite PMU militia continued their march towards the Syrian border and Deir Ezzor province yesterday.

But on Saturday the Syrian-Kurdish Democratic Union Party (PYD) leadership adviser Sihanouk Dibo reiterated that the SDF would not allow the PMU to link up with the Syrian army.

“There is no difference between Turkey, Iran and the Bashar al-Assad regime because they work against the Syrian Kurds,” he told ARA news.

And in the east of Rif Dimashq province near the Jordanian border, US-backed Free Syrian Army militants trying to prevent the regime’s’s relief of Deir Ezzor claimed that they had shot down an air-force jet fighter.