The pro-government forces had been backed by artillery, tanks and other heavy weaponry when they attacked an SDF headquarters "eight kilometres [5 miles] east of the agreed-upon Euphrates River de-confliction line", United States officials said.
US-led coalition has killed more than 100 troops allied with the Syrian regime in an overnight operation carried out in retaliation for an attack on Kurdish forces.
USA -led coalition forces are looking into whether Russian contractors were involved in an attack against Syrian Democratic Forces on Wednesday.
"Coalition advisers were with the SDF in advise, assist and accompany capacity and this action was taken in self-defense", the coalition said.
It was a rare USA strike against forces that support the Assad regime.
He said no USA personnel or coalition members had been wounded, although one SDF fighter was injured in the confrontation.
The attacks follows days of regime bombardment on rebel-held zones that have killed more 100 civilians, capturing global attention to the regime's deepening effort to reclaim opposition territory.
Consumer Reports finds Samsung, Roku TVs vulnerable to hacking
Eason Goodale is the Disconnect lead engineer. "It's as though once you unlocked your door, the door would never lock again". It said that "every smart TV we evaluated asked for permission to collect viewing data and other kinds of information".
"International coalition forces are bombing popular forces fighting "Daesh" and the SDF (Syrian Democratic Forces) east of the Euphrates river and there are reports of casualties", the statements said.
The coalition said the attack took place in Khusham in the Middle Euphrates River Valley, five miles east of the agreed-on "de-confliction" line created to separate Russian-backed regime troops and US-backed forces in Syria.
Details of the thwarted attack were released by USA officials who wished to remain anonymous.
Neither U.S. officials nor the U.S. -backed coalition have offered details on the attacking forces.
Those pro-regime vehicles and personnel who retreated across the river were not targeted, the official added.
Another US official who spoke to CNN said it was unclear exactly who the pro-regime forces were but that the US is looking into whether Russian contractors operating in the vicinity might have been involved.
Efforts were undertaken before and after the battle to avoid any confrontation with Russian military forces in the area that are backing the Assad regime in the country's long-running civil war.
Veale said it's likely the pro-regime forces were trying to seize oilfields in Khusham that had been liberated from Islamic State control in September.
Clinton campaign fed Steele info for Trump dossier - Senate Judiciary Committee
Steele's personal credibility and presumably having faith in his process of obtaining the information", it continues. Steele gathered much of his information from Russian government sources inside Russia". "It did so based on Mr.