The relative democratization of the Soviet regime under Mikhail Gorbachev's "glasnost" and "perestroika" policies since the mid-1980s gave rise to nationalism in the republics of the Soviet Union. In Armenia, the Karabakh movement gained widespread public support. Armenians demanded the Soviet authorities unify the mostly Armenian-populated Nagorno-Karabakh Autonomous Oblast (NKAO) of Azerbaijan with Armenia. In February 1988, the NKAO regional legislature requested the transfer of the region from the jurisdiction of Azerbaijan SSR to Armenian SSR, but it was rejected by the Politburo. Tensions between Armenians and Azerbaijanis further escalated with the pogrom in Sumgait. With both groups arming themselves, clashes became frequent, especially in the disputed Nagorno-Karabakh and the border areas of the two Soviet republics. In 1989 and 1990, Sargsyan took the command of Armenian volunteer groups fighting near Yeraskh, on the Armenian-Azerbaijani (Nakhchivan) border, not far from his hometown.