Ukrainian voters are going to the polls in snap elections for a new parliament.
President Petro Poroshenko called the poll as he aims to cement a new direction for the country after the ousting of pro-Russian leaders earlier this year.
But the vote will be overshadowed by a continuing conflict with pro-Russian rebels in the east.
The BBC reports that about 3 million people in Donetsk and Luhansk regions will not vote. The separatists will hold their own polls next month.
Another 1.8 million people in Crimea, annexed by Russia in March, will not take part.
The vote also comes amid an energy crisis, with Russia cutting off gas supplies to Ukraine in June in a dispute over unpaid bills.
Ukraine's economy is collapsing, with GDP forecast to fall between 7 and 10 percent this year.
Ukraine's government hopes the elections will help stabilise the country, with pro-Russian parties considerably weakened by recent events.
Half of the 450 seats in parliament will be allocated proportionally according to a party list system, with parties needing to gain more than 5 percent to win seats.
Another 198 MPs will be elected from individual constituencies, with 27 from Crimea and the rebel-held areas remaining vacant.
The main parties vying for seats are:
- Mr Poroshenko's Poroshenko Bloc, comprising his own Solidarity party and Udar, led by boxer Vitali Klitschko.
- Prime Minister Arseny Yatsenyuk's People's Front.
- Oleh Lyashko's nationalist Radical Party.
- Former Prime Minister Yulia Tymoshenko's Fatherland Party.
Most are nationalist and pro-Western, and ousted President Viktor Yanukovych's Party of Regions is not running.
However, three parties comprising his former allies are seeking votes in the south and east of the country.
"At last we will elect a pro-Ukrainian and not pro-Moscow, an anti-corruption and not pro-bribery, a pro-European parliament," Mr Poroshenko said on Friday.
Mr Yanukovych fled in February after a wave of pro-Western protests in Kiev triggered by his refusal to sign a partnership agreement with the European Union.
Anger in eastern Ukraine at his overthrow turned to unrest with separatists seizing government buildings and beginning an insurgency in April.
At least 3,700 people have been killed since the conflict began, including 300 killed after a ceasefire was agreed on 5 September.
On Friday Russian President Vladimir Putin said for the first time that Moscow had helped Mr Yanukovych flee.