The ethnic conflict began to erupt in the region. Оn 5 June 1919, 600 Armenian inhabitants of the villages surrounding Shusha were killed by Azerbaijani and Kurdish irregulars. Sultanov stated that those irregulars were not under his control. In August 1919, the Karabakh National Council was forced to enter into a provisional treaty agreement with the Azerbaijani government, recognizing the authority of the Azerbaijan government until the issue of the mountainous part of Karabakh would be settled at the Paris Peace Conference. Despite signing the Agreement, the Azerbaijani government continuously violated the terms of the treaty, employing even more severe measures against the Armenian population. Governor-General Sultanov accumulated troops in the region and on 19 February 1920 issued an ultimatum to the Armenians to accept unconditional unification with Azerbaijan, then massacred the population of several Armenian villages including Khankendi. A minority of Karabagh National Council representatives gathered in Shusha to accept Sultanov's demands, while the rest met in nearby Shushikend to reject the ultimatum. The strife culminated in an Armenian uprising, which was suppressed by the Azerbaijani army. In late March 1920, the Armenian half of the police forces was reported by a British journalist to have murdered the Azerbaijani half during the latter's traditional Novruz Bayram holiday celebrations. The Armenian surprise attack was organised and coordinated by the forces of the Armenian Republic. Azerbaijani outrage for this surprise attack ultimately led to the massacre of March 1920, in which between 500 to 20,000 of the Armenian population of Shusha was killed, and many forced to flee.