The combatants of the war in Donbas include foreign and domestic forces. As of February 2018, the number of separatist forces were estimated at 31,000 out of which 80% (25,000) were Donbas residents, 15% (≈5,000) were military contractors from Russia and other countries and 3% (900–1,000) were regular Russian armed forces personnel. This proportion has significantly changed from earlier years, with "Russian command gradually filling up the military of the 'republics' with locals" since peaking in 2015.