After the German invasion in the USSR in June 1941, the brothers organized large meetings in areas not yet taken to gather supporters. In some areas, up to 80% of men were involved in the insurrection. It is known that the Soviet Union used bombers against the rebels, causing losses primarily to the civilian population. In February 1942, Mairbek Sheripov organized rebellion in Shatoi, Khimokhk and tried to take Itum-Kale. His forces unified with Israilov's soon after, and they began taking control of areas of Western Dagestan. The insurrection caused many Chechen and Ingush soldiers of the Red Army to desert. Some sources claim that total number of deserted mountaineer soldiers reached 62,750, exceeding the number of mountaineer fighters in the Red Army.