Donetsk, Ukraine (CNN) -- As the Ukrainian military warns of plans to assault this rebel-controlled city, separatist militants are thinning on the streets and their leaders are canceling public appearances.
Inside the city, shelling has already pushed some residents underground into cellars and half-built basements.
In a dim labyrinth beneath a government building, dozens of women and children sleep on mattresses they carried below ground to take shelter from the violence.
They say they believe separatists who have told them the Ukrainian army are American-backed fascists, set on attacking ethnic Russians.
"They crush us, the damn Americans. What are they doing? Where there is war in the world, they have a part," one woman said.
Above ground, the grief and anger are more vivid, near where a school was hit.
"They are unworthy, because they are fascists, the government, why do they have to shoot innocent people?" resident Svetlana Ivanovna said.
Rima Denisovna returned home Monday to find glass covering her bed.
Ukraine's army has used a lot of artillery in its fast advance, but it's unclear who fired the shells here that shattered her windows.
Denisovna, who was staying with her daughter when the shells hit, knows one thing.
"If I'd been asleep here," she said, "I would have died."