MOSCOW, October 26. /TASS/. The Kremlin doubts the authenticity of conclusions produced by the US consultancy Soufan Center to the effect nearly 3,500 Russian citizens fight for Islamic State terrorists in Syria.

"The Kremlin rather tends to doubt the authenticity of that claim," presidential spokesman Dmitry Peskov told the media.

He explained the Kremlin had no idea what the report was based on and what sources its authors had used.

Peskov recalled that at the beginning of Russia’s operation in Syria President Vladimir Putin said Moscow saw one of the purposes of this operation to protect its security, because "several thousand Russia-born people, including those from the North Caucasus, according to our intelligence, are in the territories controlled by the Islamic State (outlawed in Russia)." Peskov recalled that Moscow at different levels noted the risk those Russian citizens who at a certain point had joined the terrorists might start returning home someday.

"Resistance to that potential threat is one of the priorities," Peskov said.

He pointed out that those who had joined the terrorists or were involved in terrorist activities somehow and confronted the Syrian army weapons in hand, let alone used them against Russian military participating in the operation were criminals and were being eliminated.

Earlier, US consultancy Soufan Center said in its report that Russia had become of the main sources of foreign mercenaries for the Islamic State to get ahead of such countries as Saudi Arabia and Jordan. The consultancy claimed that 3,417 militants of Russian descent were fighting for the Islamic State.