The Britain-based Syrian Observatory for Human Rights said an air raid "by the international coalition" hit the camp in the western Deir Ezzor province in Syria.
Four Syrian soldiers were killed and 13 injured when a bombing raid by the US-led coalition hit an army camp in the east of the country, a monitor said today.
The Britain-based Syrian Observatory for Human Rights said an air raid "by the international coalition" hit the camp in the west of Deir Ezzor province, "around two kilometres (one mile) from an area controlled by the ISIS".
The Observatory said it was the first time that a strike from the US-led coalition had killed Syrian government troops.
"Regime forces have never previously been hit by raids from the international coalition, which was targeting terrorists bases and oil tankers in Deir Ezzor," Observatory director Rami Abdel Rahman said.
The US-led coalition has been targeting ISIS in Syria since September last year, expanding a campaign that began with raids in neighbouring Iraq.
Its operations have expanded further in recent days, partly in response to the deadly attacks in Paris claimed by ISIS.
On Sunday its jets hit ISIS positions in Raqa province, killing at least 49 people, mainly terrorists, according to the Observatory.
It said that eight children and five women were killed in the raids, but that it was not clear if they were connected with ISIS.
The monitor relies on a network of activists, medical staff and fighters on the ground who identify warplanes based on model, flight patterns and munition types.
Syria's conflict has taken the lives of more than 250,000 people, and another four million have been forced to flee the country since it erupted in March 2011.