At least 103 regime troops, including 21 officers, were killed by the Islamic State in Syrian desert in July, local reporter said.
90 soldiers were from central Homs province as the clashes with east take place in the eastern countryside and the desert; also known as al-Badiya.
Since May, the regime army and allies have been conducting a broad military campaign to recapture the vast desert that separates the capital Damascus from Deir al-Zor and other towns along the Euphrates Valley.
On Sunday, Jaish Osoud al-Sharqiya killed 15 regime troops in al-Badiya when its artillery and Grad rockets pounded an army stronghold in Um Remam area, spokesman said Friday.
Said Seif, press officer of the U.S.-backed group that operates in eastern Qalamoun and al-Badiya, said 141 Grad rockets were fired on the regime bastion in the strategic Um remam area near the Iraqi border.
The surprise attack has left heavy losses in regime ranks, destroying ten armoured vehicles, he added.
Regime army and its allies on Saturday reached the edge of al-Sukhna, the last town held by Daesh (ISIS) in Homs province and a key step in their multi-pronged offensive against the militants, a Hezbollah-run military media unit said.
Sukhna is on the main desert highway between Palmyra and the government's besieged enclave at Deir al-Zor, about 130km to the east.
The Hezbollah media unit earlier said the Sukhna gas field and heights above the town were within range of the army and its allies' fire.
