DONETSK, Ukraine — When the streets of Donetsk are quiet, the supermarkets resound with the clatter of grocery carts and the rattling of cash drawers.
Elderly women approach the register with mountains of vegetable crates, bags of flour, toilet paper, and jugs of cooking oil. No one knows when they will be able to go to the store again, or if food will be there.
Residents of Donetsk have found themselves in the midst of an civil war that has split the eastern region into loyal Ukrainians and separatists, and has turned their city into the main stronghold for pro-Russia rebels. The Ukrainian army arrived in the city suburbs last week, and the two forces have exchanged artillery and mortar fire throughout neighborhoods.
"More and more people have taped up windows," said Tatiana Viktoroyna, an emergency service worker. "Some have put bed linens, others have taken the windows out altogether replacing them with plastic polythene sheets. They fear that the blasts and explosions won't stop."
On Sunday, fighting raged in the eastern Ukrainian city despite a request from the rebels for a cease-fire to prevent a "humanitarian catastrophe." Ukrainian officials demanded that the insurgents surrender instead.
One person was killed and 10 were injured in shelling that started early Sunday and continued into the day, Donetsk city council spokesman Maxim Rovinsky told The Associated Press.
In a press conference in the capital city of Kiev, Andriy Lysenko, a spokesman for Ukraine's National Security and Defense Council, said the only way for the rebels in Donetsk to save their lives would be to "lay down their arms and give up." He said the Ukrainian side hadn't seen the rebels show any real willingness to cooperate.
Fighting in eastern Ukraine began in April, one month after Russia annexed Ukraine's Black Sea region of Crimea.
During the fighting, power outages have darkened the northern part of Donetsk while the Ukrainain military occupies a main railway supply hub 12 miles north of the city center. Pro-Russia separatists have issued a statement that they will requisition cars, building materials, food and medical supplies for military use.
"People are tired of the fighting, rockets, and lawlessness," said taxi driver Andrei Maximovich. "You hear cars being commandeered. And ordinary people are forced to fill sand bags and dig trenches."
The conditions near the fighting have become so bad that between 600,000 and 750,000 Ukrainians have fled their homes for the north, west and east across the border with Russia. Refugee organizations don't know the exact number because many Ukrainians do not want to register themselves for fear of either the separatists or the Ukrainian government.
The UNHCR's European director Vincent Cochetel has urged Ukrainian authorities to set up a centralized system to expedite relief efforts. Locals say the Russians have organized it well across the border.
Meanwhile, locals say they fear the Ukrainian army.
"They Ukrainian National Guard will come and kill us." said resident Galina Vladimirovna. "People say that we are all separatists here and that those who were not separatists have already left."
Even so, that doesn't mean unconditional support here for the separatists.
"Some people here remain quiet and prefer to wait, not to speak out until it is all over," said Mr. Maximovich. "When the Ukrainian army comes in it would be best for separatists not to remain here as the people will deal with them [harshly] after all that has happened."
The control that rebel forces have exerted over Donetsk not only has separated it from the rest of the Ukraine, but also has broken apart families here as well.
"I have a sister in Kiev, a brother in Vinnytsia [in western Ukraine]," said Ms. Vladimirovna. "They've stopped talking to me."
"They say that I am with the separatists, with [Viktor] Yanukovich," she added, referring to the Ukrainian president who fled office in February after months of anti-government protests kicked off by his decision to scuttle an association agreement with the EU in favor of closer ties with Moscow. "Before we were as one, now they have divided us, and we have no way out."
• This article is based in part on wire service reports.