Residents of Lvov, Kharkov and Odessa went headed to their local polling stations on Sunday to vote in the second round of Ukrainian presidential elections.
According to data from OPORA observers, voter turnout was at 25.3 percent at 12:00 local time (9:00 GMT).
Ukrainian law forbids the publishing of exit poll data until voting is over.
Police issued Ukrainian presidential candidate... Еще Volodymyr Zelenskiy with an administrative offence for showing his ballot paper at the ballot station.
Ukrainians face a choice between incumbent leader Petro Poroshenko and comic actor Volodymyr Zelenskiy. Latest opinion polls show that the comedian is the clear favourite in the runoff election.
Zelenskiy won the first round of the presidential election on March 31, gathering 30.24 percent of the vote to Poroshenko's 15.95 percent.
Polling stations around the country are open from 08:00 local time (05:00 GMT) until 20:00 (17:00 GMT). More than 35 million people are eligible to vote in Ukraine's seventh presidential election at 30,000 polling stations.