The foreign ministry stressed that the reports were issued just as a UN chemical weapons inspection team had arrived in Syria and noted that "this makes us think that we are once again dealing with a premeditated provocation."
The foreign ministry said the claims were first reported "by partisan regional media all at once, as if by command" and argued that previous such reports had proven false.
Moscow has defended Syrian President Bashar al-Assad's regime throughout the conflict and only accused his opponents of using chemical arms.
Russia added that it was now "important to conduct an objective and professional investigation into what occurred.
