Russia on Wednesday called Syrian opposition claims of the Damascus regime launching a chemical weapons attack that killed more than 1,300 people a "premeditated provocation."
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.
The Russian ministry statement said the opposition appeared to be trying to undermine the chances of all sides agreeing to sit down for peace negotiations first mooted by Moscow and Washington in May.
Russia added that it was now "important to conduct an objective and professional investigation into what occurred."