Ukrainians are voting in local elections that are seen as a test of the strength of President Petro Poroshenko's government and of the oligarchs accustomed to running regions of the country.

The situation in Mariupol, a major port and steel city, is especially fraught. The city is torn by disputes over the influence of Rinat Akhmetov, Ukraine's richest man whose industrial holdings are key to Mariupol's economy.

The dispute led to the last-minute scrapping of Sunday's election in Mariupol, with both sides blaming the other.

Poroshenko ordered the national parliament and central elections commission to make sure the election is held soon.

Elections also were not being held in parts of eastern Ukraine controlled by Russia-backed rebels.

Elsewhere, voters are choosing more than 10,700 local councils as well as mayors.