Nearly complete election results show Ukrainian opposition leader Viktor Yanukovych winning a narrow victory in Sunday's run-off presidential election.
With almost all the ballots counted, Mr. Yanukovych has more than 48 percent of the vote compared to about 46 percent for his opponent, Prime Minister Yulia Tymoshenko.
However, Ms. Tymoshenko is refusing to concede defeat and may launch a legal challenge to the election results. Ms. Tymoshenko accused pro-Yanukovych forces of ballot-box stuffing in Russian-speaking eastern Ukraine.
For his part, Mr. Yanukovych has claimed victory in what would be an astonishing comeback for the candidate who supports closer ties with Russia.
Six years ago, official results declared Mr. Yanukovych the winner over pro-Western Viktor Yushchenko, but huge protests known as the "Orange Revolution" over reports of massive vote fraud led to a new election won by Mr. Yushchenko.
President Yushchenko took office in January 2005 with Ms. Tymoshenko as his prime minister. Their partnership later disintegrated and both ran for president this time around. Mr. Yushchenko finished well behind both Mr. Yanukovych and Ms. Tymoshenko in the first round of voting, and was not eligible for the runoff ballot.
The campaign for Sunday's election had been marked by smears and insults throughout. The two candidates accused each other of rigging the vote even before balloting began.
Mr. Yanukovych was considered the front-runner in the runoff vote, since he won the first round last month by 10 percentage points. He is a former prime minister himself, and was in office at the time of the last presidential election, in 2004.
Some information for this report provided by AP, AFP and Reuters.