Ukrainians voted on Sunday in the first round of the country's presidential election, with incumbent leader Peter Petro Poroshenko seeking re-election and a surprise front-runner, comedian Volodymyr Zelenskiy.
If no candidate gets more than 50 per cent on Sunday, the top two will fight it out in a second round on April 21, the BBC reported.
Besides Poroshenko and Zelenskiy, the third important face in the election is former Prime Minister Yulia Tymoshenko.
A total of 39 candidates are in the fray, but only the three front-runners are considered to have any chance of victory.
More than 34 million citizens are eligible to vote in nearly 30,000 polling stations, which opened at 8 a.m. Voting will end at 8 p.m.
First results of the exit polls will be announced as soon as the voting closes. Vote counting will begin at 10 p.m.
The Central Election Commission of Ukraine is expected to release primary official results on Monday morning.
The top three candidates have expressed largely pro-European views during campaigning. None of the pro-Russian candidates were being seen as serious contenders.
Poroshenko, 53, one of Ukraine's wealthiest oligarchs, was elected in a snap vote after former pro-Russian President Viktor Yanukovych was toppled in the February 2014 Maidan Revolution, which was followed by Moscow's annexation of Crimea and insurgency in eastern Ukraine.
He aims to appeal to conservative Ukrainians through his slogan "Army, Language, Faith".
Meanwhile, Zelenskiy, 41, is aiming to turn his satirical TV show, in which he portrays an ordinary citizen who becomes president after fighting corruption, into reality.
He has done no rallies with only a few interviews,and appears to have no strong political views apart from a wish to be new and different. His extensive use of social media appeals to younger voters.
Zelenskiy readiness to speak both Russian and Ukrainian has gained him support in Ukraine's largely Russian-speaking east, the BBC reported.
Tymoshenko, 58, who served as Prime Minister and ran for president in 2010 and 2014, had played a leading role in the 2004 Orange Revolution, Ukraine's first big push to ally itself with the European Union (EU).
However, opinion polls have suggested Zelenskiy will have a clear lead over Poroshenko and Tymoshenko in Sunday's first round of voting and would retain it in a run-off against either of them.
The next President will inherit a deadlocked conflict between Ukrainian troops and Russian-backed separatists in the east, while Ukraine strives to fulfil EU requirements for closer economic ties.
The EU has said that about 12 per cent of Ukraine's 44 million people are disenfranchised, largely those who live in Russia and in Crimea.
Separatist-controlled areas are boycotting the election.
