President Vladimir Putin has denied that Russian air strikes are hitting moderate opposition groups rather than Islamic State militants.
Speaking to Russian state TV, Mr Putin defended Russia's military operations in Syria, and said the aim was to support President Bashar al-Assad.
"By no means do we want to get involved in any inter-religious conflicts in Syria," he said. "We have only one goal which is to support the local authorities (ie Assad's regime), and create conditions for political settlement."
He said the overall aim was to "stabilise the legitimate authority" is Assad's regime. He said that without Moscow's support for President Assad there was a danger that "terrorist groups" could overrun Syria.
The US-led coalition which has also been carrying out air strikes in Syria has said it would mot be co-operating with Russia.