Syrian state media reported early Thursday that an aerial attack by the US-led coalition had hit several military positions in the country's east, but said there were no casualties.
"Some of our military positions between Albu Kamal and Hmeimeh were hit this morning in an aggression by American coalition warplanes," said a military source quoted on state news agency SANA.
The source told SANA the attack only caused "material damage."
Albu Kamal and Hmeimeh lie in Syria's eastern Deir Ezzor province, where Russian-backed Syrian troops and the US-led coalition have been waging separate offensives against the Islamic State group.
A "de-confliction" line in place since last year is meant to keep the two assaults from crashing into each other, and runs along the Euphrates River.
Regime troops are present west of the river while the US-backed Syrian Democratic Forces (SDF) are on the east.
A military source from forces allied to Syria's government said the strikes had targeted two regime military positions near a frontline with IS.
"Daesh then launched an attack on the positions. The strikes and attack left a number of Syrian fighters dead and caused material damage," the source told AFP, using the Arabic acronym for IS.
"There are no Iranian or Lebanese fighters among the dead," the source said.
The coalition has carried out several deadly strikes against Syrian government forces and allied fighters in recent months.
In February, coalition bombing raids in Deir Ezzor province killed at least 100 regime and allied fighters, including Russian nationals, in retaliation for an attack on SDF positions.
And in September 2016, US-led strikes on regime military positions in the east left more than 60 Syrian troops dead. The coalition later said it had mistaken the fighters for IS jihadists.
There was no immediate comment on Thursday from either the US-led coalition or the SDF, which are fighting to clear IS from a final series of villages on the eastern bank of the Euphrates.
IS overran swathes of Syria and neighbouring Iraq in 2014, but separate offensives across both countries have seen its grip on territory shrink dramatically.
On Monday, Syrian troops and allied forces ousted IS from the last districts it held in the capital Damascus.
After a fierce month-long battle, an evacuation deal saw the remaining diehard jihadists bussed out of the city towards small pockets of land still held by IS in Syria's Badiya.
The Badiya is the vast desert stretching from the country's centre to its eastern border with Iraq.
The day after the transfer, IS fighters in the Badiya launched an attack on a nearby government position, leaving more than two dozen Syrian troops and allied fighters dead.