 After the Sino-Soviet split, the Soviet Union amassed troops on the Russian border with Xinjiang, and bolstered "East Turkestan" separatist movements, which received moral and material support from other regional militant groups.China accused the Soviets of engineering riots, and improved the military infrastructure there to combat it.In the 1980s, Chinese authorities relaxed some of its repressive policies against ethnic minorities, and loosened border controls which allowed Uyghurs to travel to the Mecca Pilgrimage.