Ukrainian President Petro Poroshenko's ruling coalition faces a test of its record so far in local elections. But as separatist eastern regions boycotted the poll, voting in nearby Mariupol was said to be on hold.
The municipal polls in Ukraine come during a period of relative calm in fighting.
Twenty months have passed since the ex-Soviet nation attracted worldwide attention through protests that ultimately toppled Kremlin-backed leader Viktor Yanukovych, and resulted in Russia's subsequent annexation of Crimea.
The pro-Moscow eastern revolt that followed resulted in more than 8,000 deaths, including those who died in the crash of flight MH17, and saw Ukraine stripped of strategic naval bases and its industrial heartland in the east. With worries growing that the country could be slipping off the global radar, Ukraine also became Europe's second-poorest country. Many fear that the situation in the east of the country could turn into a "frozen conflict" with terms dictated by Russian President Vladimir Putin.
With the prospect of Kyiv ever winning back the Crimean peninsula looking increasingly unlikely, Ukrainian President Petro Poroshenko's Solidarity party has started to flag in opinion polls - to the benefit of his opposition, including pro-Russian movements.
Meanwhile, the separatist parts of the Russian-speaking Luhansk and Donetsk regions announced that they were boycotting the polls and planning their own for next year. The insurgents said they intended to bar pro-Kyiv candidates from their elections and accused Poroshenko of orchestrating a "genocide."
Elections cancelled in Mariupol
Voting offices stayed closed in the key port city of Mariupol, the government's last bastion in rebel-held eastern Ukraine. It later emerged that the local elections were cancelled in Mariupol because of what officials described as a lack of sufficient ballots in the disputed industrial city. A statement from Poroshenko's Solidarity party said the polls "were aborted for formal reasons - due to the improper preparation of election ballots, the absence of control over their printing and number, and reliable storage."
Electoral commission member Natalia Kashchiy told the AFP news agency that polling stations did not open in Mariupol "because the ballots were not ready in the voting offices."
But polls showed that pro-Russian groups were also gaining momentum because of Kyiv's economic blockade of rebel-run regions, where an estimated 3.5 million people still live. Poroshenko's party said it still hoped to conduct mayoral and regional council elections in the city in the coming weeks.
The city of nearly 500,000 people has become a focal point of pro-Russian rebel attacks. Mariupol provides a vital land bridge between separatist regions in the southeast and Crimea - the Ukrainian peninsula seized by Russia a month after the February 2014 ouster of Moscow-backed president Viktor Yanukovych.
The popularity of Poroshenko's government plunged over time due to hikes in utility bills and other austerity measures prescribed by world lenders under the $40 billion (36 billion euro) economic rescue loan given to Ukraine in the wake of the Crimea crisis and the conflict in the nation's eastern region. Poroshenko's confident promise to stamp out the insurgency within a matter of days announced on the day after his presidential triumph has clearly failed, resulting in frustration and animosity among the electorate.
Poroshenko's leadership has suffered several setbacks since the start of the ongoing conflict in Ukraine
Prime Minister Arseniy Yatsenyuk - a top Poroshenko coalition partner - has also seen his own approval languishing at an estimated two percent. His party even decided not to provide any candidates in the mayoral and local legislature races in apparent fear of a humiliating defeat.
The public's frustration at the West's refusal to arm Ukrainian forces and only provide tightly-regulated financial help has further bolstered the election odds of the marginalized but militant far right. The demoralized mood of voters has been picked up by an astounding 132 parties.
ss/rc (AFP, dpa)