3,5 thousand people in Afghanistan joined ISIS. This was told by the chief of General Staff of the Russian Armed Forces Lieutenant General Igor Korobov, TASS reports. "Strengthening the positions of ISIS in Afghanistan raises a special concern. At this stage, there are about 3.5 thousand people in the ranks of the Islamists, "he said. According to Korobov, terrorists intend to increase their strength at least twice by 2018.