Leaders of Islamic State militants are moving more forces into western Syria from neighboring regions and even countries, MoD spokesman said, adding that Russian drones have registered terrorists troops’ movement into the west of the country from northern Raqqa province and from Iraq.

Reporting on its activities in Syria against Islamic State (IS, formerly ISIS) jihadists and other terrorists, Russia’s Defense Ministry denied US allegations that cluster bombs had been used during the operation in areas with civilian population.

On Wednesday, speaking on the advances of the Russian operation in Syria, the MoD also mentioned that a new challenge had been observed by its intelligence. IS commanders have been in talks with members of other terrorist groups, including Al-Nusra Front, to unite their forces against Syrian government troops, Konashenkov said.