Ukraine Crisis Threatens Rift Between Us and Russia

Ukraine's political crisis deepened last night after three days of street protests and political drama threatened to cause a diplomatic rift between Russia and the US.

The opposition leader, Viktor Yushchenko, declared himself the winner of Sunday's presidential run-off against the Kremlin-backed prime minister, Viktor Yanukovich, by swearing himself in after an emergency parliamentary session. The EU and the US tacitly backed Mr Yushchenko's claims by stepping up pressure for a review of the election, which western observers have said was seriously flawed. "The US is deeply concerned by extensive and credible indications of fraud," said a White House spokeswoman.

But President Vladimir Putin of Russia, visiting Portugal, branded criticism of the election "inadmissible" as there were still no complete official results. Ukraine did not need to be lectured, he said.

The US summoned the Russian ambassador to explain why they had endorsed a victory for Mr Yanukovich before the count was completed. In turn, a Russian official lashed out at what he called "unprecedented interference" in domestic affairs.

Opposition protesters shouted "Bravo Mr President!" as Mr Yushchenko swore an oath on the constitution and a bible. The speaker of parliament, Volodymyr Lytvyn, called Mr Yushchenko's move a "political act," which "cannot entail any legal consequences."

Mr Yushchenko accused Ukrainian authorities of rigging Sunday's vote and announced a campaign of civil disobedience. "Ukraine is on the threshold of a civil conflict," Mr Yushchenko said. "We have two choices: the answer will be given by the parliament, or the streets will give an answer."

Thousands of protesters surrounded the presidential offices in Kiev to demand that the election results be overturned. They were met by hundreds of police in riot gear.

Late last night the protests appeared to be calming after the outgoing president, Leonid Kuchma, called for negotiations with the opposition.

Earlier, Yushchenko supporters had followed him to parliament, waving orange flags and chanting. Others set up tents on Kiev's main avenue and in Independence Square, pledging to stay until he is declared president. Five trucks full of rubble were parked nearby and men inside two parked buses described them selves as "volunteers to prevent a coup d'etat".

Kiev's city council and the administrations of four other cities - Lviv, Ternopil, Vinnytsia and Ivano-Frankivsk - have refused to recognise the figures from the central electoral commission giving Mr Yanukovich a commanding lead.