The rebel forces are soldiers recruited from the Russian segment of the Ukraine, some with advanced training in Russia. According to some reports, actual citizens of Russia are involved, especially in the operation of the more sophisticated hardware.
They may be regarded as "terrorists" (Ukraine government) or "criminals" (some of the western press) or rebels, but they consider themselves to be Russian patriots.

Their missiles shot down two more Ukraine jets today; the Ukraine seems unable to use airpower against the Separatists.

Here in Alberta, with a large Ukrainian population (350,000) in the central belt centered on Edmonton, events are being closely watched. The fear is that the entire Ukraine will eventually be reabsorbed by Russia.