FILE PHOTO: A fighter from Deir al-Zor military council which fights under the Syrian Democratic Forces (SDF) holds the council's flag in the village of Abu Fas, Hasaka province, Syria September 9, 2017. REUTERS/Rodi Said/File Photo

MOSCOW (Reuters) - Russia’s Defence Ministry on Sunday rejected allegations it had bombed U.S.-backed militias in Syria, saying its planes only targeted Islamic State militants and that it had warned the United States well in advance of its operational plans.

U.S.-backed militias said they came under attack on Saturday from Russian jets and Syrian government forces in Deir al-Zor province, a flashpoint in an increasingly complex battlefield.

The Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias fighting with the U.S.-led coalition, said six of its fighters had been wounded in the strike.

But Major-General Igor Konashenkov, a spokesman for the Russian Defence Ministry, dismissed the allegations in a statement on Sunday.

Konashenkov said Russian planes had only carried out carefully targeted strikes in the area based upon information that had been confirmed from multiple sources.

The strikes had only hit targets in areas under the control of Islamic State, he said.

“To avoid unnecessary escalation, the commanders of Russian forces in Syria used an existing communications channel to inform our American partners in good time about the borders of our military operation in Deir al-Zor,” Konashenkov said.

“In the last few days, Russian surveillance and reconnaissance did not detect a single clash between Islamic State and armed representatives of any ‘third force’ on the eastern bank of the Euphrates,” he added.

Separately, Franz Klintsevich, a member of the upper house of parliament’s security committee, said there was no proof to underpin the accusations against Moscow.