By AFP - May 24,2018 - Last updated at May 24,2018

Pro-government forces attend a flag raising ceremony at the entrance of Al Hajar Al Aswad neighbourhood on the southern outskirts of the capital Damascus on Thursday, after the regime seized the Yarmouk Palestinian camp and adjacent neighbourhoods of Tadamun and Al Hajar Al Aswad earlier in the week from Daesh, putting Damascus fully under its control for the first time since 2012 (AFP photo)

BEIRUT, Lebanon — A US-led coalition air strike on Syrian army positions overnight killed at least 12 pro-regime fighters in an area where both sides have been battling holdout militants, a monitor said on Thursday.

Syrian state media reported the strike but said it only caused material damage, while the Pentagon said it had “no information to substantiate those reports”.

The Britain-based Syrian Observatory for Human Rights, which relies on a broad network of sources across Syria, said the raid had hit army positions south of Albu Kamal, a town on Syria’s border with Iraq.

“At least three vehicles were destroyed by the strike,” said observatory chief Rami Abdel Rahman.

He said the 12 pro-regime fighters killed in the incident were not Syrians, but he could not provide more details on their identity.

A military source quoted by state news agency SANA said that “some of our military positions between Albu Kamal and Hmeimeh were hit this morning in an aggression by American coalition warplanes”.

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 Daesh militant group.

A “de-confliction” line in place along the Euphrates River since last year is meant to keep the two assaults from crashing into each other.

Loyalist 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 Daesh.

Repeated incidents

“There are no Iranian or Lebanese fighters among the dead,” the source said.

Iraqi Shiite militia are also fighting alongside Syrian regime forces in the area.

The observatory said the government was sending reinforcements.

It was not immediately clear whether militants were active in the area at the time, nor whether the pro-regime casualties may have been accidental.

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 Daesh militants.

Daesh group has lost nearly all the territory it once controlled in Syria and Iraq but it still holds some villages in the Euphrates Valley area.

On Monday, Syrian troops and allied forces ousted Daesh from the last districts it held in the capital Damascus.

After a fierce month-long battle, an evacuation deal saw the remaining militants bussed out of the city towards small pockets of land still held by Daesh in the Badiya, a vast desert area stretching from central Syria to its eastern border with Iraq.

The day after the transfer, Daesh militants in the Badiya attacked a nearby government position, leaving more than two dozen Syrian troops and allied fighters dead.

The observatory said the Daesh militants responsible were from the group that had just been transferred out of the Yarmouk area in southern Damascus.