Russian President Vladimir Putin has congratulated a Moscow-backed candidate on being elected as president of Ukraine, though Western observers say the vote-counting was rigged and tens of thousands of people are protesting the results.

The Interfax news agency quoted Putin's press secretary as saying Putin phoned Victor Yanukovich Monday and declared his victory "convincing."

With 99.14 per cent of precincts counted, Ukraine's Central Election Commission had in effect declared victory for Yanukovich, whom it said was three percentage points ahead of rival Victor Yushchenko.

Viktor Yushchenko addresses a crowd at Kiev's Independence square, accusing authorities of rigging the presidential vote,Monday. (AP photo)

But earlier Western-financed exit polls had put Western-leaning candidate Yushchenko 11 percentage points ahead of the Moscow-backed Yanukovich, and Yushchenko claimed the authorities were attempting to steal his victory by cheating.

Speaking to an estimated 100,000 people in central Kyiv's Independence Square, he called on his supporters to wage a campaign of civil disobedience until his victory was recognized.

"We will not leave this place until we win," he told the crowd. "The people's will cannot be broken. People's votes cannot be stolen."

Richard Lugar

Kyiv's city council quickly passed a resolution calling on the national parliament not to recognize Yanukovich as the winner of the election.

Meanwhile, the cities of Lviv, Ternopil and Vinnytsia announced that they will recognize Yushchenko as president.

OSCD says election flawed

Rally at Kyiv's Independence square. (AP photo)

The Organization for Security and Co-operation in Europe, which had been monitoring Sunday's poll, said Monday that the election had not conformed to "democratic norms."

"The second round did not meet a considerable number of [international] commitments for democratic elections," said Bruce George, head of the OSCE mission, which has 600 observers in the country.

And Richard Lugar, head of the U.S. Senate foreign relations committee, said the Ukrainian authorities had supported concerted fraud in Sunday's presidential election.

"It is now apparent that there was a concerted and forceful program of election day fraud and abuse enacted with the leadership or co-operation of authorities," said Lugar

"We've had many reports of irregularities," Motria Onyschuk-Moroz, a Canadian election observer in Ukraine, told CBC Newsworld. "Many people were turned away during election day and had to contest their right to vote in court. They were forced to wait for hours in long lines at the courts."

• FROM NOV. 21, 2004: Both candidates declare victory in Ukraine vote

Adding to the confusion, armoured personnel carriers were reported to have taken up defensive positions around the presidential palace still inhabited by outgoing President Leonid Kuchma, and the offices of the election commission.

Conflicting views of vote outcome

Yushchenko had earlier charged the authorities with blatant falsification to ensure victory for the prime minister.

"I believe in my victory but the government...has staged total fraud in the elections in the [eastern] Donetsk and Lugansk regions," Yushchenko said in a statement.

"I do not trust the Central Electoral Commission," he added.

Chanting "shame, shame, shame," thousands of Yushchenko's supporters heeded his call for a mass morning rally in the main square of the capital, Kyiv.

Ukraine's Central Electoral Commission chief, Serhiy Kivalov, urged all politicians to calm down.

"The [commission] will act strictly in conformity with the law," the BBC reported Kivalov as saying.

The election is seen by many analysts as a pivotal moment in Ukraine's recent history, one that could put the country of 48 million people on a path of integration with Europe or send it back into the orbit of Russia.

The United States and the European Union have warned Kyiv they would rethink their relations with Ukraine if the election falls below acceptable democratic standards.