"Four past reports of possible civilian casualties and three of the reports received in October were determined to be credible resulting in the unintended death of 54 civilians," the report stated.
"To date, based on information available, CJTF-OIR [Combined Joint Task Force — Operation Inherent Resolve] has assessed it is more likely than not that, since the start of Operation Inherent Resolve, 173 civilians have been inadvertently killed by coalition strikes," the report stated.
The list of casualties included a July 18 airstrike near the Syrian city of Manbij that killed 24 civilians "who had been interspersed with combatants" in a Daesh staging area. The Central Command said the civilians were not observed in the area on the day before the strike.
Reports prior to the airstrike had indicated that 100 Daesh terrorists were preparing for a counterattack against Syrian Democratic Forces fighters, Central Command explained.
The Central Command determined 12 reports of civilian casualties were non-credible and is still assessing three others.
Earlier this week, the Pentagon stated that the US-led coalitions airstrikes on the Syrian army positions were an "unintentional, regrettable error."
Earlier, the Russian Defense Ministry slammed the US-led coalition for striking civilians instead of terrorists.
"Weddings, funerals, hospitals, police departments, humanitarian convoys and even Syrian troops, fighting against Daesh terrorists near Deir ez-Zor, become targets for coalition airstrikes," spokesman Maj. Gen. Igor Konashenkov said, commenting on an alleged US-led coalition's member's strike on a Syrian village in north Aleppo that claimed at least six lives.