Syrian government troops on Friday launched a new push towards the eastern Deir Ezzor military airport, which has remained under a years-long siege by the Islamic State group.

Jihadists had encircled two regime-held enclaves in the western half of Deir Ezzor city, which is the capital of the strategic and oil-rich province by the same name.

The army this week broke through one of the besieged pockets by seizing the Brigade 137 base on the western edge of the city.

On Friday, troops began a push to reach the second encircled area, which includes the Deir Ezzor military airport on the city's southern edge.

"The operation to break the siege on the military base began at noon today," a Syrian military source in the city said.

The source said troops from Brigade 137 had advanced south and were now fighting in Deir Ezzor's vast cemetery, about one kilometre (less than a mile) northwest of the air base.

"And southwest of the airport, the army has already seized the town of Al-Shoula," about 40 kilometres from the base, the source said.

"It will aim to open a route between (government-held parts of the) city, the military airport, and the eastern neighbourhoods" still under IS control, the source added.

Since 2014, IS has held swathes of Deir Ezzor province, which border Iraq, and about 60 percent of the provincial capital.

Syria's government remained in control of the strategic military airport and several neighbourhoods in the city home to about 100,000 people, whom IS put under crippling siege.

Syrian military aircraft had flown in assistance and other supplies on several occasions but the process was hampered by security concerns and damage to the military airport by IS fire.

The United Nations also airdropped aid into the city dozens of times since April 2016, but humanitarian organisations had been unable to access Deir Ezzor by land until Friday.

On Friday, 42 trucks loaded with food, medicine, hygiene kits for tens of thousands of needy civilians entered the city, the Syrian Arab Red Crescent said in a statement.

The previous day, foodstuff supplied by the Syrian Trade Association was delivered to Deir Ezzor via the road newly opened by Syria's forces when they broke the IS encirclement.

Source: AFP