On Saturday, organizers in Donetsk and Luhansk continued preparations, distributing leaflets and posters urging people to vote. Those planning the referendum say Friday's attack by government forces that killed as many as 20 people in the port city of Mariupol will not disrupt the vote.
“We will not let an attack happen. We are not afraid of anyone, this is our Donbass [the region surrounding Donetsk] and we will oppose anyone who comes here," said separatist fighter Igor Banderenko. "We will free this area and then we will go to Slovyansk, Mariupol, Luhansk and release them as well.”
Luhansk's separatist leader, Valery Bolotov, told Russia's Interfax news service he expects a 90 percent voter turnout for Sunday's ballot, which seek approval for so-called sovereign people's republics in the regions of Luhansk and Donetsk, the largest city in eastern Ukraine. The vote — organized on an ad hoc basis with no clear controls over ballot papers or voter lists — has been widely criticized by Kyiv and Western capitals.
Separatist leaders say residents of Donetsk and Luhansk are demanding the immediate opportunity to vote on the region's future, despite questions about the legality of the ballots and recent polling showing 70 percent of locals oppose secession.
Addressing international media at a recently assembled electoral commission headquarters, Roman Lyagin displayed a black and white referendum ballot that asks if the voter supports declaration "of self-rule by the Donetsk People's Republic.” It had no special markings to prevent duplication, leaving opening the possibility of massive electoral fraud.
“I might get 15 years in prison for doing this," Lyagin said, explaining that his social beliefs led him to organize the poll and head the electoral commission. "All that I care about here is making peace on my own land. My child lives here. I don't want bloodshed here. How else can I guarantee the legitimacy? I don't know."
Separatist forces claim the referendum is the only hope of keeping the conflict from spiraling out of control. But with doubts about the validity of the ballot, some have expressed concern that it may have exactly the opposite effect.
Story continues below photo gallery: On Saturday, interim Ukrainian President Oleksandr Turchynov warned secession supporters that independence would be "a step into the abyss for these regions." He also appealed to rebels to join talks on greater autonomy in the east.
Also on Saturday, rebel activists in Donetsk released seven Red Cross workers they had detained late Friday. The separatists had indicated earlier they believed the Red Cross team was engaged in espionage.
Warning for Moscow
Western leaders blame Moscow for encouraging the separatist movement, and Saturday German Chancellor Angela Merkel and French President Francois Hollande said they would back new economic sanctions against Moscow if the ongoing unrest threatens Ukraine's May 25 presidential election. During a joint press conference Saturday in Germany's Baltic port of Stralsund, the two leaders also called the referendum illegitimate.
Meanwhile, reporters in the southeastern Ukrainian port city of Mariupol say Ukrainian security forces have withdrawn to the outskirts of the city, less than a day after attacking a police facility occupied by separatists.
Witnesses say Friday's fighting, described as one of the bloodiest military operations of the secession crisis, left at least seven people dead. Television footage later showed the police headquarters reduced to smoldering rubble.
The French news agency on Saturday described the center of the city of nearly 500,000 residents as "a post-apocalyptic wasteland," with young men building makeshift barricades around charred buildings.
Russian President Vladimir Putin has urged organizers to delay Sunday's vote; but that recommendation appears to have been rejected, leaving it unclear how or if Moscow will respond should secessionists prevail.
The United States, which does not recognize the annexation, condemned Putin's visit, which Ukraine's Foreign Ministry called a "provocation."