There no "rebels" in Ukraine, it`s moscvin mercenarties and regular moscvin army dressed as "rebels" and max few thousands of former Ukrainian citizens (majority of them are ethnic moscvins already with moscvin passports ,posterity of those who were moved to Ukraine after moscovia starved to death at least 5mln of Ukrainians in 1932-1933 and a bit of ethnic Ukrainian traitors). Those former citizens of Ukraine are not separatists also, they are colaborators. It`s all was started by saboteurs from moscovia in 2014 and has been fully controlled by moscow all this almost 6 years. moscovia has been supplying ammunition, weapons, equipment and more for almost 6 years.
In summer of 2014 Ukrainian volunteers and balances of regular Ukrainian army that moscow agency did not have time to sell and destroy in decades of formal, conditional Ukrainian independence, liberated most of the territories occupied by moscvin saboteurs.
And then , moscovia entered parts of its regular army, including tanks and artillery in August.