Two exit polls are predicting victory for Ukraine's pro-western opposition leader Viktor Yushchenko in Sunday's presidential run-off election, though the polls differ widely on the margin of victory

One exit poll, conducted by the Kiev Institute of Sociology and the Razumkov Center for Economic and Political Studies, shows Mr.Yushchenko ahead of Ukraine's Moscow-leaning Prime Minister Viktor Yanukovich by a double-digit margin

But the Interfax news agency quotes another exit poll showing Mr.Yushchenko ahead by less than four percentage points.

But both sides are claiming numerous instances of voting irregularities.

In the first round of voting last month, neither candidate won a majority, but Mr. Yushchenko alleged voting fraud had cost him the election.

Some information for this report provided by AP, AFP and Reuters.