There are fears American-backed anti-IS forces have been hit by Russian aircrafts carrying out their first bombing missions in Syria.

Reports said at least one group, labelled as “Syrian opposition fighters”, who had been trained by the CIA, were hit in the attacks.

The New York Times reported a senior US official said at least one and maybe more opposition groups “secretly armed and trained by the CIA” were hit by Russia in the strikes.

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“The official would not identify which group or groups were attacked or where they were located,” the report said.

“Nor would he assess the damages or casualties suffered by the Syrian fighters other than to say, ‘It was not minor’.

“[The attacks have been] eliciting angry protests from American officials and plunging the complex sectarian war there into dangerous new territory.”

Russian SU-24 bombers are said to have been used for the strikes. Photo: Getty

The American officials indicated they were still assessing battle damage reports to see if any other US backed groups had been hit. 

The CIA’s “covert” program to train fighters has reportedly produced 3,000 to 5,000 troops in Syria in the past two years.

This program is separate from the Pentagon’s $500 million effort to train Syrian fighters, which the New York Times described as having “largely failed”.

Russian President Vladimir Putin justified his country’s bombing by saying it was operating “preventatively, to fight and destroy militants and terrorists on the territories that they already occupied, not wait for them to come to our house”.

Russia and the United States offered conflicting accounts of which targets had been struck, underlining growing tensions between the two former Cold War foes over Moscow’s decision to intervene.

The US said it believed Russia had targeted the opposition rebels threatening Syria’s embattled leader Bashar al-Assad — not IS as claimed.

“We have not seen any strikes against ISIL, what we have seen is strikes against [the] Syrian opposition,” a US defence official said, using an alternative name for IS.

However, Russian defence ministry spokesman Igro Konashenkov said Russian fighter jets carried out 20 flights, striking eight IS targets, including weapons depots, ammunition, communications infrastructure and fuel.

A US official said Moscow gave Washington just an hour’s notice of the strikes, which the Kremlin said were designed to help Mr Assad — its closest regional ally — push back Islamist militants.

Here’s a graphic, explaining how the complex fight is playing out:

Photo: ABC

– with ABC