The Ukrainian military now surrounds Donetsk, which the rebels re-named the Donetsk People's Republic.
Military spokesman Andriy Lysenko expressed concern that the rebels were mistreating the residents of Donetsk. Rebels have forced some to take up arms against the military; in other instances, they have kidnapped and killed residents, seizing control of their homes.
The military has established humanitarian corridors to facilitate the evacuation of civilians out of eastern Ukraine. Lysenko added that the government would help evacuees find temporary shelter.
It is unclear when the military will move in to liberate Donetsk but with Monday's evacuation warning, the assault could be imminent.