A Russian military official has claimed that weapons from the US have ended up in the hands of Syrian rebels.
Gen Nikolai Makarov said to the Interfax news agency that the origin of surface-to-air anti-aircraft missiles, including US-made Stingers, should be “cleared up”.
"We have reliable information that Syrian militants have foreign portable anti-aircraft missile systems, including those made in the USA... it should be cleared up who delivered them," Gen Makarov told reporters.
Russia is the largest supplier of arms to the Syrian regime.
In other developments, UN special envoy Lakhdar Brahimi announced that the Syrian government and opposition groups will observe a ceasefire to mark the Muslim festival of Eid al-Adha.
"After the visit I made to Damascus, there is agreement from the Syrian government for a ceasefire during the Eid," he told reporters on Wednesday.
"Other factions in Syria that we were able to contact - heads of fighting groups - most of them also agree on the principle of the ceasefire."
