On February 20, 1988, the extraordinary session of Nagorno Karabakh Autonomous Oblast (NKAO) People's Deputies resolved “to petition the Supreme Councils of the Azerbaijani SSR and Armenian SSR on transfer of the NKAO to Armenian SSR.”

A week later the Azerbaijani authorities launched pogroms of the Armenian population in Sumgait, killing 32 and injuring hundreds of people according to official data.

On September 2, 1990, Nagorno Karabakh proclaimed independence. The national liberation movement resulted in formation of independent Republic of Artsakh.