The army men pushed ISIS back from the strategic town of al-Sukhnah Northeast of Palmyra city after hours of clashes in the town's neighborhoods.
ISIS has suffered heavy casualties in the operation, the sources added.
They went on to say that the army's engineering units are now defusing landmines and bombs planted by the ISIS in the town's streets and buildings.
In the meantime, the Syrian Air Force has been targeting ISIS positions in the town of Humeimeh and its surrounding areas near the provincial border with Deir Ezzur province, inflicting major casualties on the terrorists.
Reports said earlier today that the army troops engaged in very tough battle with ISIS terrorists in different neighborhoods of the key town of al-Sukhnah and managed to impose control over more positions.
The army men clashed fiercely with ISIS in the last stronghold of the terrorists in Eastern Homs and captured the Western neighborhood of the town.
Also, the army units advanced against ISIS from the Southern flank and seized control over the town's hospital.
Meantime, a military source said that al-Sukhnah is under the army's siege from the South, South-West and South-East, adding that the army men plan to advance towards Bazaar following the capture of the hospital.
The source added that the army has dispatched a large number of forces and a large volume of equipment from Quneitra to al-Sukhnah.
The source went on to say that a large number of ISIS terrorists have been killed or wounded and their military hardware has been destroyed in the battle.