Tensions have snowballed between the Ukrainian army and pro-Russian militants Friday, after a prolonged standoff at a Donetsk airport resulted in the deaths of 34 Russian fighters.
In a startling announcement, several separatists admitted earlier this week that pro-Russian forces include not only Ukrainian nationals, but also Russian citizens.
The announcements raise questions about Moscow's official role in the conflict, after Russia has been accused multiple times of facilitating the unrest to fulfill a long-term political agenda.
In the meantime, analysts have warned of an all-out civil war in the region, as the pro-Russian militias prepare to defend themselves against the Ukrainian army.
"The ruins of the airport are under the control of Kiev," the ruler of the self-proclaimed "Donetsk's People's Republic," Alexander Borodai, stated to the Kyiv Post Friday. "Tremendous enemy forces are concentrated in that area."
"We can't collect all the bodies from the airport as it is cordoned off," he added. "The city is ready for defense."
Infighting has erupted between the pro-Russian and pro-Ukrainian militias within Donetsk, he said - not only between local militias and Ukrainian soldiers.
"[We are fighting] not Kyiv, but the battalions of the Dnipropetrovsk oligarch [and Jewish mayor Igor] Kolomoisky," he said.
Pro-Russian separatists used anti-aircraft weapons to shoot down a Ukrainian helicopter on Thursday, killing fourteen people - including a major general.
Up to 40,000 Russian troops have been rumored to be at the ready on the Russian-Ukrainian border over the past month, as violence raged in Ukraine's eastern districts.
A landmark deal reached last month between Russia, the US and the European Union (EU) called for the separatists, who have been seizing government buildings in eastern Ukraine for several days, to disarm and stand down - in exchange for amnesty.
Russian President Vladimir Putin has also stated multiple times that he would retract his forces from the border - pacifying the West - on the condition that separatists stand down.
The pro-Russian protesters have largely ignored the deal, however, claiming that the agreement does not apply to them.
Calls for a full-fledged separation and change in national loyalty follow the controversial annexation of the Crimean peninsula several months ago, after a de facto military invasion sparked an uprising in the former Ukrainian territory.