“We feel serious concern over the information that Russia’s air strikes in Syria targeted opposition positions instead of Daesh (IS) and that as a result civilians also lost their lives,” Sinirlioglu said, quoted by the state-run Anatolia news agency.

“If these reports are confirmed, then this is a very worrying development.

“This would escalate the crisis and is the last thing we need in Syria’s tragic and chaotic environment,” he said.

“In this case… the problems will increase for the Syrian people.”

Russia on Wednesday launched air strikes in war-torn Syria, saying it wanted to target IS jihadists.

But US Defence Secretary Ashton Carter said all evidence indicated that the IS group was not the target of Wednesday’s strikes, which took place in provinces with a limited IS presence.

Russian Foreign Minister Sergei Lavrov earlier Thursday rejected accusations that Moscow had bombed moderate rebel factions fighting President Bashar al-Assad instead of IS fighters.

Turkey has long supported the rebel factions in the hope that they are the best hope of achieving Ankara’s strategic aim of ousting Assad.

Russia, by contrast, is along with Iran Assad’s chief international ally and Moscow has long insisted that the Syrian leader should be part of any solution.