As fighting between separatists and the Ukrainian government worsened in Donbass, their membership rose to 350, and later 4,000.[3] Notable engagements of the ROA include the June 2014 skirmishes in Mariupol and Amvrosiivka Raion.[7] The headquarters of the ROA is located in an occupied Security Service of Ukraine (SBU) building in Donetsk city.[8] Members had no special training apart from the usual conscription service in the army[9] and swore allegiance to Igor Girkin ("Strelkov"), insurgent and Minister of Defence of the self-declared Donetsk People's Republic.