The Russian warplanes pounded ISIS strongholds in al-Tamanna in the Northwestern governorate of Idlib, sources said on Sunday. The sources said that the ISIS terrorist group sustained heavy losses in the Russian airstrikes in Idlib, particularly in al-Tamanna area. The sources said that the air attacks have significantly laid the ground for the Syria army's ground operation to retake the control of the area. Also on Saturday, the Syrian fighter jets bombed concentration centers and hideouts of the foreign-backed Takfiri militants in Idlib countryside, inflicting heavy losses on them. The airstrikes hit terrorists' positions in Khan Sheikhoun city, Tal Merei and in the towns of al-Hbeit and al-Tamanaa.