According to the Russian Defense Ministry, warplanes targeted eight ISIS positions, including arms, transportation, communications and control positions.
But U.S. Defense Secretary Ash Carter countered that claim.
"I want to be careful about confirming information, but it does appear that they (Russian airstrikes) were in areas where there probably were not ISIL forces," he told reporters. ISIL is an acronym for ISIS.
"The result of this kind of action will inevitably, simply be to inflame the civil war in Syria," Carter said.
A senior U.S. administration official told CNN's Elise Labott that a Russian airstrike near the Syrian city of Homs "has no strategic purpose" in terms of combating ISIS, which "shows they are not there to go after ISIL."
