Ukraine's opposition has challenged the results of Sunday's presidential election in an appeal to the country's Supreme Court as tens of thousands of protesters crowd Kiev and other cities for a fourth straight day.
Opposition presidential candidate Viktor Yushchenko filed the formal complaint Thursday. Election officials declared pro-Russian Prime Minister Viktor Yanukovych the victor in the election, with slightly more than 49 percent of the vote. But Mr. Yushchenko has rejected the results and has called for a general strike, saying his country is "on the verge of civil conflict".
Opposition leaders in Kiev say their supporters are already blocking roads in some parts of Ukraine.
Former Polish President and Solidarity Trade union leader Lech Walesa is in Kiev to mediate the dispute.