DONETSK, Ukraine — Standing in a small park and holding a Soviet flag, Nikolai Brilyov, an enthusiastic member of the breakaway People’s Republic of Donetsk, spent Sunday immersed in civic duties. There was an oligarch to run out of town, and political rallies to attend. None of it, however, included voting in the presidential election.

“That happened in Ukraine,” he explained. “We don’t live there anymore.”

If western Ukrainians see the vote as the culmination of months of struggle against a corrupt government, many in the troubled east see it as legitimizing a division of the country that began in February with the overthrow of the government in Kiev and that deepened this month with a rudimentary referendum for self-rule in two eastern provinces.

In Donetsk, the most populous region in the country, just 2 percent of registered voters cast ballots on Sunday, according to the Committee of Voters of Ukraine, a nonprofit organization whose workers monitored the vote.

The tiny turnout had much to do with separatist interventions. For days leading up to the vote, armed men closed polling stations and seized voter lists, elections stamps and sometimes even poll workers. In all, only a fifth of the region’s polling stations were open on Sunday, with a turnout at those of about 12 percent, according to the committee.