Russia's Foreign Ministry has called for a thorough investigation into reports that Syrian government forces had launched a chemical attack.
The Foreign Ministry suggested that rebels could have staged the assault to provoke international action.
Syria's opposition accused President Bashar al-Assad's forces of gassing many hundreds of people on Wednesday.
If confirmed, the gas attack would be the world's worst chemical weapons attack in decades.
According to news24, Foreign Ministry spokesperson Alexander Lukashevich said that its sources in Syria said that a homemade rocket carrying unidentified chemical substances had been launched from an area controlled by the opposition.
Russia has also demanded that a UN investigation into the alleged use of chemical weapons also look into possible use by rebels, the report added.