Russia's UN envoy said Tuesday he has handed over evidence to the United Nations which indicates Syrian rebels used sarin gas in an attack in March.
The envoy, Vitaly Churkin, said Russian experts had been to the scene of the attack at Khan al-Assal near Aleppo and had gathered firsthand evidence.
The Syrian government has refused to let a UN inspection team into the country, but this week invited UN officials for talks on launching an investigation.
Churkin told reporters the Russian inquiry had "established" that rebel forces had fired a Bashar 3 missile at the town, killing 26 people including 16 troops.
"The results of the analysis clearly indicate that the ordinance used in Khan al-Assal was not industrially manufactured and was filled with sarin," Churkin added.
Britain, France and the United States say they have handed over evidence to UN experts that President Bashar al-Assad's forces have used chemical weapons in the 26-month-old conflict.
Up to 100,000 people have been killed in Syria since the uprising against President Bashar al-Assad began in March 2011, according to UN figures.