WESTERN governments have accused Russia of targeting moderate Syrian opposition groups rather than Islamic State with its airstrikes in support of the beleaguered regime of Bashar Assad.

Russian jets carried out a second day of strikes in Syria, with some claiming the targets included rebels backed by the United States.

Russia's Defence Ministry said its aircraft damaged or destroyed 12 targets in Syria belonging to the Islamic State group including a command centre and two ammunition depots.

However a senior US official said the strikes had taken place in the western part of Syria beyond the city of Homs, where there was no IS presence, and appeared to be aimed at other opposition groups.

Representatives of various western states, along with Syrian opposition groups, have also cast doubt on whether IS has taken the brunt of the attacks.

French defence minister Jean-Yves Le Drian said: "Curiously, they didn't hit Islamic State. I will let you draw a certain number of conclusions yourselves."

Prime Minister David Cameron said it would be a "retrograde step" if the Russians hit moderate opposition forces like the Western-backed Free Syrian Army.

Khaled Khoja, head of the Syrian National Council opposition group, said at the UN that Russian airstrikes in four areas, including Talbiseh, killed 36 civilians, with five children among the dead. The claim could not be independently verified.

The British-based Syrian Observatory for Human Rights also said airstrikes in the central province of Hama on Thursday hit locations of the US-backed rebel group, Tajamu Alezzah.

Speaking during a visit to Jamaica, Mr Cameron said the UK Government would need to look "very carefully" at exactly what had happened on the ground in Syria.

"I have a clear view that if this is a part of international action against Isil, that appalling terrorist death cult outfit, then that is all to the good," he said.

"If, on the other hand, this is action against the Free Syrian Army in support of Assad the dictator, then obviously that is a retrograde step but let us see exactly what has happened."

Russian President Vladimir Putin denied reports that civilians were killed in any Russian airstrikes.

"We are ready for such information attacks," he said in a live broadcast from the Kremlin. "The first reports of civilian casualties came even before our jets took off."

Mr Putin also said Russia would be fighting "gangs of international terrorists".

The Syrian civil war, which grew out of an uprising against Mr Assad, has killed more than 250,000 people since March 2011 and sent millions of refugees fleeing to other countries in the Middle East and Europe.

While the US and Russia agree on the need to fight the Islamic State but there is no common ground regarding an approach to President Assad.

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