The government-controlled Syrian Central Military Media said troops are marching south from Deir el-Zour toward Mayadeen under the cover of airstrikes.
In another air strike, more than 60 mercenaries from the former Soviet Union, Tunisia, and Egypt were killed in the Euphrates Valley south of Deir Ezzor, according to AFP.
Islamic State has staged fierce counter-attacks in central Syria in recent days, testing the army's control of an area seized in a months-long eastward offensive.In June, two USA intelligence officials told Reuters that they believed Islamic State had moved most of its diminished command structure and propaganda team to al-Mayadin, southeast of its former capital of Raqqa. Gen. Igor Konashenkov, said IS militants have used the area around the town of Tanf near Syria's border with Jordan where US military instructors are also stationed to launch attacks against the Syrian army.
About 80 terrorists died in a raid on a command post in the al-Mayadeen area of Deir ez-Zor province, the ministry added, saying that 40 militants were killed near the border town of al-Bukamal, also in Deir ez-Zor.
Mayadeen is one of the ISIS group's last bastions in Syria.
Attempted murder charges against suspect in Edmonton attack
Sharif is charged with five counts of attempted murder and four counts of risky operation of a motor vehicle causing bodily harm. On Monday, an unmarked police vehicle was parked in front of the plain three-storey building listed as Mr.
MOSCOW, Oct. 7 (Xinhua) - About 120 Islamic State (IS) militants and more than 60 foreign mercenaries in Syria were killed in airstrikes launched by Russia over the past 24 hours, the Russian Defense Ministry said Saturday.
Syria's official SANA news agency reported Thursday that army units had engaged Daesh terrorists on the al-Mayadin-Day al-Zawr road and the surrounding areas, inflicting heavy losses on the militants and their military equipment.
The village of Abu Dali had been spared much of the violence and had functioned as a local business hub between rebel-run areas and those under President Bashar Assad's forces.
The Syrian military shelled Mayadeen overnight and Syrian and Russian warplanes have conducted hundreds of strikes, it said.
Over the course of months of successive defeats, Mayadeen and nearby Albu Kamal on the Iraqi border have taken in IS fighters fleeing the battle to the north for Raqa city in the face of an offensive launched by US-backed Kurdish and Arab forces.